diff --git a/deps/ox/src/ox/fs/filesystem/passthroughfs.cpp b/deps/ox/src/ox/fs/filesystem/passthroughfs.cpp
index 4cc7aa90..365d5bb7 100644
--- a/deps/ox/src/ox/fs/filesystem/passthroughfs.cpp
+++ b/deps/ox/src/ox/fs/filesystem/passthroughfs.cpp
@@ -185,8 +185,7 @@ Error PassThroughFS::writeFileInode(uint64_t, const void*, uint64_t, FileType) n
 }
 
 std::string_view PassThroughFS::stripSlash(StringView path) noexcept {
-	const auto pathLen = ox::strlen(path);
-	for (auto i = 0u; i < pathLen && path[0] == '/'; i++) {
+	for (auto i = 0u; i < path.len() && path[0] == '/'; i++) {
 		path = substr(path, 1);
 	}
 	return {path.data(), path.bytes()};
diff --git a/release-notes.md b/release-notes.md
index 57449ad4..e9c37a9c 100644
--- a/release-notes.md
+++ b/release-notes.md
@@ -4,6 +4,8 @@
 * Add PaletteV5 to accommodate namespace change.
 * Add TileSheetV5. TileSheetV5 retains the bpp field for the sake of
   CompactTileSheet, but always store it pixel as 8 bpp for itself.
+* Add ability to move subsheets in the subsheet tree.
+* Add Flip X and Flip Y button for TileSheet Editor.
 * Replace file picker combo boxes with a browse button and file picker, and
   support for dragging files from the project explorer.
 * Add ability to create directories.
@@ -12,3 +14,4 @@
 * Ctrl-<num key> keyboard shortcuts for jumping between tabs.
 * Fix Palette Editor to ignore keyboard input when popups are open.
 * Palette Editor move color mechanism now uses drag and drop.
+* Add ability to reorder Palette pages.
diff --git a/sample_project/Palettes/Dirt.npal b/sample_project/Palettes/Dirt.npal
index ffb649e5..a53b907e 100644
--- a/sample_project/Palettes/Dirt.npal
+++ b/sample_project/Palettes/Dirt.npal
@@ -1 +1,28 @@
-K1;0f75977f-1c52-45f8-9793-52ea2dc200a0;M2;net.drinkingtea.nostalgia.core.Palette;1;
ûÿ³Ö
+K1;0f75977f-1c52-45f8-9793-52ea2dc200a0;O1;net.drinkingtea.nostalgia.gfx.Palette;5;{
+	"colorNames" : 
+	[
+		"Color 1",
+		"Color 2"
+	],
+	"pages" : 
+	[
+		{
+			"colors" : 
+			[
+				{
+					"a" : 1,
+					"b" : 31,
+					"g" : 31,
+					"r" : 31
+				},
+				{
+					"a" : 1,
+					"b" : 22,
+					"g" : 22,
+					"r" : 22
+				}
+			],
+			"name" : "Page 1"
+		}
+	]
+}
\ No newline at end of file
diff --git a/sample_project/Palettes/Logo.npal b/sample_project/Palettes/Logo.npal
index 6e2cb29f..3e70d034 100644
--- a/sample_project/Palettes/Logo.npal
+++ b/sample_project/Palettes/Logo.npal
@@ -1 +1,36 @@
-K1;c79f21e2-f74f-4ad9-90ed-32b0ef7da6ed;M2;net.drinkingtea.nostalgia.core.Palette;1;

PÛ{³ÖCˆ
+K1;c79f21e2-f74f-4ad9-90ed-32b0ef7da6ed;O1;net.drinkingtea.nostalgia.gfx.Palette;5;{
+	"colorNames" : 
+	[
+		"Color 1",
+		"Color 2",
+		"Color 3",
+		"Color 4"
+	],
+	"pages" : 
+	[
+		{
+			"colors" : 
+			[
+				{
+					"b" : 5
+				},
+				{
+					"b" : 22,
+					"g" : 22,
+					"r" : 22
+				},
+				{
+					"b" : 27,
+					"g" : 27,
+					"r" : 27
+				},
+				{
+					"b" : 20,
+					"g" : 8,
+					"r" : 8
+				}
+			],
+			"name" : "Page 1"
+		}
+	]
+}
\ No newline at end of file
diff --git a/sample_project/TileSheets/Logo.nts b/sample_project/TileSheets/Logo.nts
index 7c6be746..824bbd02 100644
Binary files a/sample_project/TileSheets/Logo.nts and b/sample_project/TileSheets/Logo.nts differ
diff --git a/src/nostalgia/modules/gfx/include/nostalgia/gfx/tilesheet.hpp b/src/nostalgia/modules/gfx/include/nostalgia/gfx/tilesheet.hpp
index 3a67adc2..30355112 100644
--- a/src/nostalgia/modules/gfx/include/nostalgia/gfx/tilesheet.hpp
+++ b/src/nostalgia/modules/gfx/include/nostalgia/gfx/tilesheet.hpp
@@ -289,7 +289,7 @@ constexpr ox::Error repair(TileSheetV4 &ts) noexcept {
 
 
 struct TileSheetV5 {
-	using SubSheetIdx = ox::Vector<std::size_t, 4>;
+	using SubSheetIdx = ox::Vector<uint32_t, 4>;
 
 	struct SubSheet {
 		static constexpr auto TypeName = "net.drinkingtea.nostalgia.gfx.TileSheet.SubSheet";
@@ -445,23 +445,25 @@ TileSheet::SubSheetIdx validateSubSheetIdx(TileSheet const&ts, TileSheet::SubShe
 
 [[nodiscard]]
 TileSheet::SubSheet const&getSubSheet(
-		TileSheet::SubSheetIdx const&idx,
+		ox::SpanView<uint32_t> const&idx,
 		std::size_t idxIt,
 		TileSheet::SubSheet const&pSubsheet) noexcept;
 
 [[nodiscard]]
 TileSheet::SubSheet &getSubSheet(
-		TileSheet::SubSheetIdx const&idx,
+		ox::SpanView<uint32_t> const&idx,
 		std::size_t idxIt,
 		TileSheet::SubSheet &pSubsheet) noexcept;
 
 [[nodiscard]]
-TileSheet::SubSheet const&getSubSheet(TileSheet const&ts, TileSheet::SubSheetIdx const&idx) noexcept;
+TileSheet::SubSheet const&getSubSheet(TileSheet const&ts, ox::SpanView<uint32_t> const &idx) noexcept;
 
 [[nodiscard]]
-TileSheet::SubSheet &getSubSheet(TileSheet &ts, TileSheet::SubSheetIdx const&idx) noexcept;
+TileSheet::SubSheet &getSubSheet(TileSheet &ts, ox::SpanView<uint32_t> const &idx) noexcept;
 
-ox::Error addSubSheet(TileSheet &ts, TileSheet::SubSheetIdx const&idx) noexcept;
+ox::Error addSubSheet(TileSheet &ts, TileSheet::SubSheetIdx const &idx) noexcept;
+
+ox::Error insertSubSheet(TileSheet &ts, ox::SpanView<uint32_t> const &idx, TileSheet::SubSheet ss) noexcept;
 
 ox::Error rmSubSheet(
 		TileSheet &ts,
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt b/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
index cdaf9d3e..25e3a79c 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/CMakeLists.txt
@@ -1,18 +1,6 @@
-target_sources(
-	NostalgiaCore-Studio PRIVATE
-		commands/addcolorcommand.cpp
-		commands/addpagecommand.cpp
-		commands/applycolorallpagescommand.cpp
-		commands/duplicatepagecommand.cpp
-		commands/movecolorcommand.cpp
-		commands/removecolorcommand.cpp
-		commands/removepagecommand.cpp
-		commands/renamepagecommand.cpp
-		commands/updatecolorcommand.cpp
-		commands/updatecolorinfocommand.cpp
-)
-
 target_sources(
 	NostalgiaCore-Studio-ImGui PRIVATE
 		paletteeditor-imgui.cpp
 )
+
+add_subdirectory(commands)
\ No newline at end of file
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/CMakeLists.txt b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/CMakeLists.txt
new file mode 100644
index 00000000..42c4cd54
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/CMakeLists.txt
@@ -0,0 +1,15 @@
+
+target_sources(
+    NostalgiaCore-Studio PRIVATE
+        addcolorcommand.cpp
+        addpagecommand.cpp
+        applycolorallpagescommand.cpp
+        duplicatepagecommand.cpp
+        movecolorcommand.cpp
+        movepagecommand.cpp
+        removecolorcommand.cpp
+        removepagecommand.cpp
+        renamepagecommand.cpp
+        updatecolorcommand.cpp
+        updatecolorinfocommand.cpp
+)
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
index 7ca6ee69..666a0f20 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/commands.hpp
@@ -12,6 +12,7 @@ enum class PaletteEditorCommandId {
 	AddPage,
 	DuplicatePage,
 	RemovePage,
+	MovePage,
 	AddColor,
 	RemoveColor,
 	UpdateColorInfo,
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp
new file mode 100644
index 00000000..86a9c80d
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#include "commands.hpp"
+
+#include "movepagecommand.hpp"
+
+namespace nostalgia::gfx {
+
+MovePageCommand::MovePageCommand(
+		Palette &pal,
+		size_t const srcIdx,
+		size_t const dstIdx) noexcept:
+	m_pal(pal),
+	m_srcIdx(srcIdx),
+	m_dstIdx(dstIdx) {}
+
+int MovePageCommand::commandId() const noexcept {
+	return static_cast<int>(PaletteEditorCommandId::MovePage);
+}
+
+ox::Error MovePageCommand::redo() noexcept {
+	movePage(m_srcIdx, m_dstIdx);
+	return {};
+}
+
+ox::Error MovePageCommand::undo() noexcept {
+	movePage(m_dstIdx, m_srcIdx);
+	return {};
+}
+
+void MovePageCommand::movePage(
+		size_t const srcIdx, size_t const dstIdx) noexcept {
+	auto page = std::move(m_pal.pages[srcIdx]);
+	std::ignore = m_pal.pages.erase(srcIdx);
+	m_pal.pages.emplace(dstIdx, std::move(page));
+}
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp
new file mode 100644
index 00000000..0b42161d
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/commands/movepagecommand.hpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#pragma once
+
+#include <studio/studio.hpp>
+
+#include <nostalgia/gfx/palette.hpp>
+
+namespace nostalgia::gfx {
+
+class MovePageCommand: public studio::UndoCommand {
+	private:
+		Palette &m_pal;
+		std::size_t const m_srcIdx = 0;
+		std::size_t const m_dstIdx = 0;
+
+	public:
+		MovePageCommand(Palette &pal, size_t srcIdx, size_t dstIdx) noexcept;
+
+		~MovePageCommand() noexcept override = default;
+
+		[[nodiscard]]
+		int commandId() const noexcept override;
+
+		ox::Error redo() noexcept override;
+
+		ox::Error undo() noexcept override;
+
+	private:
+		void movePage(size_t srcIdx, size_t dstIdx) noexcept;
+};
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp b/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
index 28d1275a..8a433078 100644
--- a/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/paletteeditor/paletteeditor-imgui.cpp
@@ -11,6 +11,7 @@
 #include "commands/applycolorallpagescommand.hpp"
 #include "commands/duplicatepagecommand.hpp"
 #include "commands/movecolorcommand.hpp"
+#include "commands/movepagecommand.hpp"
 #include "commands/removecolorcommand.hpp"
 #include "commands/removepagecommand.hpp"
 #include "commands/renamepagecommand.hpp"
@@ -19,6 +20,7 @@
 
 #include "paletteeditor-imgui.hpp"
 
+
 namespace nostalgia::gfx {
 
 namespace ig = studio::ig;
@@ -33,6 +35,16 @@ OX_MODEL_BEGIN(ColorDragDrop)
 	OX_MODEL_FIELD(i)
 OX_MODEL_END()
 
+struct PageDragDrop {
+	static constexpr auto TypeName = "nostalgia.gfx.PageDragDrop";
+	static constexpr auto TypeVersion = 1;
+	uint32_t page{};
+};
+
+OX_MODEL_BEGIN(PageDragDrop)
+	OX_MODEL_FIELD(page)
+OX_MODEL_END()
+
 void PaletteEditorImGui::PageRenameDialog::draw(turbine::Context &tctx) noexcept {
 	if (!m_show) {
 		return;
@@ -235,6 +247,16 @@ void PaletteEditorImGui::drawPagesEditor() noexcept {
 			if (ImGui::Selectable("##PageRow", i == m_page, ImGuiSelectableFlags_SpanAllColumns)) {
 				m_page = i;
 			}
+			std::ignore = ig::dragDropSource([this, i] {
+				ImGui::Text("%s", m_pal.pages[i].name.c_str());
+				return ig::setDragDropPayload(PageDragDrop{i});
+			}, ImGuiDragDropFlags_SourceAllowNullID);
+			if (ig::DragDropTarget const d; d) {
+				auto const [src, err] = ig::getDragDropPayload<PageDragDrop>();
+				if (!err) {
+					std::ignore = pushCommand<MovePageCommand>(m_pal, src.page, i);
+				}
+			}
 		}
 	}
 	ImGui::EndTable();
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/CMakeLists.txt b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/CMakeLists.txt
index df125ef6..f8f42c87 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/CMakeLists.txt
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/CMakeLists.txt
@@ -5,6 +5,7 @@ target_sources(
 		deletetilescommand.cpp
 		drawcommand.cpp
 		flipcommand.cpp
+		movesubsheetcommand.cpp
 		inserttilescommand.cpp
 		palettechangecommand.cpp
 		rmsubsheetcommand.cpp
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/commands.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/commands.hpp
index 5d8302eb..4cdebe6b 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/commands.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/commands.hpp
@@ -15,9 +15,10 @@ enum class CommandId {
 	AddSubSheet,
 	RmSubSheet,
 	DeleteTile,
-	FlipXCommand,
-	FlipYCommand,
+	FlipX,
+	FlipY,
 	InsertTile,
+	MoveSubSheet,
 	UpdateSubSheet,
 	Cut,
 	Paste,
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.cpp
index b359e70a..b84b0f6a 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.cpp
@@ -2,10 +2,63 @@
  * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
  */
 
+#include <cmath>
+
 #include "drawcommand.hpp"
 
 namespace nostalgia::gfx {
 
+constexpr void iterateLine(ox::Point const &a, ox::Point const &b, auto const &f) noexcept {
+	auto const rise = b.y - a.y;
+	auto const run = b.x - a.x;
+	auto const slope = static_cast<double>(rise) / static_cast<double>(run);
+	auto y = static_cast<double>(a.y);
+	auto const w = abs(run);
+	if (rise > 0) {
+		if (run > 0) {
+			auto constexpr xmod = 1;
+			for (int32_t i = 0; i < w; ++i) {
+				auto const climb = static_cast<int32_t>(ceil(y + slope - y));
+				f(a.x + i * xmod, static_cast<int32_t>(y), climb * xmod);
+				y += slope * xmod;
+			}
+		} else if (run < 0) {
+			auto constexpr xmod = -1;
+			for (int32_t i = 0; i < w; ++i) {
+				auto const climb = static_cast<int32_t>(floor(y + slope - y));
+				f(a.x + i * xmod, static_cast<int32_t>(y), climb * xmod);
+				y += slope * xmod;
+			}
+		} else {
+			f(a.x, a.y, rise);
+		}
+	} else if (rise < 0) {
+		if (run > 0) {
+			auto constexpr xmod = 1;
+			for (int32_t i = 0; i < w; ++i) {
+				auto const climb = static_cast<int32_t>(floor(y + slope - y));
+				f(a.x + i * xmod, static_cast<int32_t>(y), climb * xmod);
+				y += slope * xmod;
+			}
+		} else if (run < 0) {
+			auto constexpr xmod = -1;
+			for (int32_t i = 0; i < w; ++i) {
+				auto const climb = static_cast<int32_t>(ceil(y + slope - y));
+				f(a.x + i * xmod, static_cast<int32_t>(y), climb * xmod);
+				y += slope * xmod;
+			}
+		} else {
+			f(a.x, a.y, rise - 1);
+		}
+	} else {
+		auto const xmod = run > 0 ? 1 : -1;
+		for (int32_t i = 0; i < w; ++i) {
+			f(a.x + i * xmod, static_cast<int32_t>(y), 1);
+		}
+	}
+}
+
+
 DrawCommand::DrawCommand(
 		TileSheet &img,
 		TileSheet::SubSheetIdx subSheetIdx,
@@ -21,7 +74,7 @@ DrawCommand::DrawCommand(
 DrawCommand::DrawCommand(
 		TileSheet &img,
 		TileSheet::SubSheetIdx subSheetIdx,
-		ox::Vector<std::size_t> const&idxList,
+		ox::SpanView<std::size_t> const&idxList,
 		int palIdx) noexcept:
 		m_img(img),
 		m_subSheetIdx(std::move(subSheetIdx)),
@@ -32,11 +85,12 @@ DrawCommand::DrawCommand(
 	}
 }
 
-bool DrawCommand::append(std::size_t idx) noexcept {
+bool DrawCommand::append(std::size_t const idx) noexcept {
 	auto &subsheet = getSubSheet(m_img, m_subSheetIdx);
 	if (m_changes.back().value->idx != idx && getPixel(subsheet, idx) != m_palIdx) {
 		// duplicate entries are bad
-		auto existing = ox::find_if(m_changes.cbegin(), m_changes.cend(), [idx](auto const&c) {
+		auto existing = find_if(
+			m_changes.cbegin(), m_changes.cend(), [idx](auto const&c) {
 			return c.idx == idx;
 		});
 		if (existing == m_changes.cend()) {
@@ -48,7 +102,7 @@ bool DrawCommand::append(std::size_t idx) noexcept {
 	return false;
 }
 
-bool DrawCommand::append(ox::Vector<std::size_t> const&idxList) noexcept {
+bool DrawCommand::append(ox::SpanView<std::size_t> const&idxList) noexcept {
 	auto out = false;
 	for (auto idx : idxList) {
 		out = append(idx) || out;
@@ -56,6 +110,26 @@ bool DrawCommand::append(ox::Vector<std::size_t> const&idxList) noexcept {
 	return out;
 }
 
+void DrawCommand::lineUpdate(ox::Point a, ox::Point b) noexcept {
+	std::ignore = undo();
+	m_changes.clear();
+	auto &ss = getSubSheet(m_img, m_subSheetIdx);
+	if (a.x < b.x) { ++b.x; }
+	if (a.y < b.y) { ++b.y; }
+	if (a.x > b.x) { --b.x; }
+	iterateLine(a, b, [this, &ss](int32_t const x, int32_t const y, int32_t const h) {
+		int const mod = h < 0 ? -1 : 1;
+		auto const range = h * mod;
+		for (int32_t i{}; i < range; ++i) {
+			auto const idx = ptToIdx(x, y + i * mod, ss.columns * TileWidth);
+			if (idx < ss.pixels.size()) {
+				m_changes.emplace_back(static_cast<uint32_t>(idx), getPixel(ss, idx));
+			}
+		}
+	});
+	std::ignore = redo();
+}
+
 ox::Error DrawCommand::redo() noexcept {
 	auto &subsheet = getSubSheet(m_img, m_subSheetIdx);
 	for (auto const&c : m_changes) {
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.hpp
index 21cf845a..a9945e72 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/drawcommand.hpp
@@ -33,12 +33,14 @@ class DrawCommand: public TileSheetCommand {
 		DrawCommand(
 				TileSheet &img,
 				TileSheet::SubSheetIdx subSheetIdx,
-				ox::Vector<std::size_t> const&idxList,
+				ox::SpanView<std::size_t> const&idxList,
 				int palIdx) noexcept;
 
 		bool append(std::size_t idx) noexcept;
 
-		bool append(ox::Vector<std::size_t> const&idxList) noexcept;
+		bool append(ox::SpanView<std::size_t> const&idxList) noexcept;
+
+		void lineUpdate(ox::Point a, ox::Point b) noexcept;
 
 		ox::Error redo() noexcept final;
 
@@ -52,4 +54,4 @@ class DrawCommand: public TileSheetCommand {
 
 };
 
-}
\ No newline at end of file
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/flipcommand.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/flipcommand.cpp
index 6acc1274..a3fd2ac8 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/flipcommand.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/flipcommand.cpp
@@ -31,7 +31,7 @@ ox::Error FlipXCommand::undo() noexcept {
 }
 
 int FlipXCommand::commandId() const noexcept {
-	return static_cast<int>(CommandId::FlipXCommand);
+	return static_cast<int>(CommandId::FlipX);
 }
 
 TileSheet::SubSheetIdx const &FlipXCommand::subsheetIdx() const noexcept {
@@ -62,7 +62,7 @@ ox::Error FlipYCommand::undo() noexcept {
 }
 
 int FlipYCommand::commandId() const noexcept {
-	return static_cast<int>(CommandId::FlipYCommand);
+	return static_cast<int>(CommandId::FlipY);
 }
 
 TileSheet::SubSheetIdx const &FlipYCommand::subsheetIdx() const noexcept {
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.cpp
new file mode 100644
index 00000000..d251d93a
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#include "movesubsheetcommand.hpp"
+
+namespace nostalgia::gfx {
+
+MoveSubSheetCommand::MoveSubSheetCommand(
+	TileSheet &img,
+	TileSheet::SubSheetIdx src,
+	TileSheet::SubSheetIdx dst) noexcept:
+		m_img{img},
+		m_src{std::move(src)},
+		m_dst{std::move(dst)} {
+}
+
+ox::Error MoveSubSheetCommand::redo() noexcept {
+	m_active = &m_dst;
+	TileSheet::SubSheet ss = std::move(getSubSheet(m_img, m_src));
+	OX_RETURN_ERROR(rmSubSheet(m_img, m_src));
+	return insertSubSheet(m_img, m_dst, std::move(ss));
+}
+
+ox::Error MoveSubSheetCommand::undo() noexcept {
+	m_active = &m_src;
+	TileSheet::SubSheet ss = std::move(getSubSheet(m_img, m_dst));
+	OX_RETURN_ERROR(rmSubSheet(m_img, m_dst));
+	return insertSubSheet(m_img, m_src, std::move(ss));
+}
+
+int MoveSubSheetCommand::commandId() const noexcept {
+	return static_cast<int>(CommandId::MoveSubSheet);
+}
+
+TileSheet::SubSheetIdx const&MoveSubSheetCommand::subsheetIdx() const noexcept {
+	return *m_active;
+}
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.hpp
new file mode 100644
index 00000000..06fc9dd9
--- /dev/null
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/commands/movesubsheetcommand.hpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2016 - 2025 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#pragma once
+
+#include "commands.hpp"
+
+namespace nostalgia::gfx {
+
+class MoveSubSheetCommand: public TileSheetCommand {
+	private:
+		TileSheet &m_img;
+		TileSheet::SubSheetIdx m_src;
+		TileSheet::SubSheetIdx m_dst;
+		TileSheet::SubSheetIdx *m_active = &m_dst;
+
+	public:
+		MoveSubSheetCommand(TileSheet &img, TileSheet::SubSheetIdx src, TileSheet::SubSheetIdx dst) noexcept;
+
+		ox::Error redo() noexcept final;
+
+		ox::Error undo() noexcept final;
+
+		[[nodiscard]]
+		int commandId() const noexcept final;
+
+		[[nodiscard]]
+		TileSheet::SubSheetIdx const&subsheetIdx() const noexcept override;
+
+};
+
+}
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
index c45a6692..fe4bece9 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp
@@ -15,6 +15,16 @@ namespace nostalgia::gfx {
 
 namespace ig = studio::ig;
 
+struct SubSheetRef {
+	static constexpr auto TypeName = "nostalgia.gfx.studio.SubSheetRef";
+	static constexpr auto TypeVersion = 1;
+	TileSheet::SubSheetIdx subsheet{};
+};
+
+OX_MODEL_BEGIN(SubSheetRef)
+	OX_MODEL_FIELD(subsheet)
+OX_MODEL_END()
+
 struct TileSheetEditorConfig {
 	static constexpr auto TypeName = "net.drinkingtea.nostalgia.gfx.studio.TileSheetEditorConfig";
 	static constexpr auto TypeVersion = 1;
@@ -142,6 +152,12 @@ void TileSheetEditorImGui::keyStateChanged(turbine::Key const key, bool const do
 			setCutEnabled(false);
 			setPasteEnabled(false);
 			m_model.clearSelection();
+		} else if (key == turbine::Key::Alpha_E) {
+			m_tool = TileSheetTool::Line;
+			setCopyEnabled(false);
+			setCutEnabled(false);
+			setPasteEnabled(false);
+			m_model.clearSelection();
 		} else if (key == turbine::Key::Alpha_S) {
 			m_tool = TileSheetTool::Select;
 			setCopyEnabled(true);
@@ -204,7 +220,7 @@ void TileSheetEditorImGui::draw(studio::StudioContext&) noexcept {
 	ImGui::BeginChild("Controls", {s_palViewWidth - 8, paneSize.y}, true);
 	{
 		auto const controlsSize = ImGui::GetContentRegionAvail();
-		ImGui::BeginChild("ToolBox", {s_palViewWidth - 24, 30}, true);
+		ImGui::BeginChild("ToolBox", {0, 32}, true);
 		{
 			auto const btnSz = ImVec2{45, 14};
 			if (ImGui::Selectable("Select", m_tool == TileSheetTool::Select, 0, btnSz)) {
@@ -220,11 +236,19 @@ void TileSheetEditorImGui::draw(studio::StudioContext&) noexcept {
 				m_tool = TileSheetTool::Fill;
 				m_model.clearSelection();
 			}
+			ImGui::SameLine();
+			if (ImGui::Selectable("Line", m_tool == TileSheetTool::Line, 0, btnSz)) {
+				m_tool = TileSheetTool::Line;
+				m_model.clearSelection();
+			}
+			//ImGui::SameLine();
+			//size_t i{};
+			//ig::ComboBox("##Operations", ox::Array<ox::CStringView, 1>{"Operations"}, i);
 		}
 		ImGui::EndChild();
-		ImGui::BeginChild("OperationsBox", {s_palViewWidth - 24, ig::BtnSz.y + 17}, true);
+		ImGui::BeginChild("OperationsBox", {0, 32}, true);
 		{
-			auto constexpr btnSz = ImVec2{55, ig::BtnSz.y};
+			auto constexpr btnSz = ImVec2{55, 16};
 			if (ig::PushButton("Flip X", btnSz)) {
 				oxLogError(m_model.flipX());
 			}
@@ -309,6 +333,16 @@ void TileSheetEditorImGui::drawSubsheetSelector(
 	                 | (rowSelected ? ImGuiTreeNodeFlags_Selected : 0);
 	ImGui::TableNextColumn();
 	auto const open = ImGui::TreeNodeEx(lbl.c_str(), flags);
+	std::ignore = ig::dragDropSource([&subsheet, &path] {
+		ImGui::Text("%s", subsheet.name.c_str());
+		return ig::setDragDropPayload(SubSheetRef{path});
+	});
+	if (ig::DragDropTarget const dragDropTarget; dragDropTarget) {
+		auto const [ref, err] = ig::getDragDropPayload<SubSheetRef>();
+		if (!err) {
+			oxLogError(m_model.moveSubSheet(ref.subsheet, path));
+		}
+	}
 	ImGui::SameLine();
 	if (ImGui::IsItemClicked()) {
 		setActiveSubsheet(path);
@@ -330,7 +364,7 @@ void TileSheetEditorImGui::drawSubsheetSelector(
 		ImGui::Text("--");
 	}
 	if (open) {
-		for (auto i = 0ul; auto &child : subsheet.subsheets) {
+		for (uint32_t i{}; auto &child : subsheet.subsheets) {
 			path.push_back(i);
 			ImGui::PushID(static_cast<int>(i));
 			ig::IndentStackItem	const indentStackItem{-indentReduce};
@@ -427,6 +461,9 @@ void TileSheetEditorImGui::drawTileSheet(ox::Vec2 const&fbSize) noexcept {
 				case TileSheetTool::Fill:
 					m_view.clickFill(fbSize, clickPos(winPos, mousePos));
 					break;
+				case TileSheetTool::Line:
+					m_view.clickLine(fbSize, clickPos(winPos, mousePos));
+					break;
 				case TileSheetTool::Select:
 					m_view.clickSelect(fbSize, clickPos(winPos, mousePos));
 					break;
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.hpp
index ea42f57f..f338408d 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditor-imgui.hpp
@@ -45,7 +45,7 @@ class TileSheetEditorImGui: public studio::Editor {
 				[[nodiscard]]
 				constexpr bool isOpen() const noexcept { return m_show; }
 		};
-		static constexpr float s_palViewWidth = 300;
+		static constexpr float s_palViewWidth = 335;
 		studio::StudioContext &m_sctx;
 		turbine::Context &m_tctx;
 		ox::Vector<ox::String> m_paletteList;
@@ -58,6 +58,7 @@ class TileSheetEditorImGui: public studio::Editor {
 		ox::Vec2 m_prevMouseDownPos;
 		TileSheetTool m_tool = TileSheetTool::Draw;
 		bool m_palPathFocused{};
+		ox::Vector<ox::UPtr<studio::UndoCommand>, 1> m_deferredCmds;
 
 	public:
 		TileSheetEditorImGui(studio::StudioContext &sctx, ox::StringParam path);
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.cpp
index 99ab1b70..954ef891 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.cpp
@@ -11,18 +11,19 @@
 
 #include <nostalgia/gfx/ptidxconv.hpp>
 
-#include "commands/commands.hpp"
 #include "commands/addsubsheetcommand.hpp"
+#include "commands/commands.hpp"
 #include "commands/cutpastecommand.hpp"
 #include "commands/deletetilescommand.hpp"
 #include "commands/drawcommand.hpp"
+#include "commands/flipcommand.hpp"
 #include "commands/inserttilescommand.hpp"
 #include "commands/palettechangecommand.hpp"
 #include "commands/rmsubsheetcommand.hpp"
 #include "commands/updatesubsheetcommand.hpp"
 #include "tilesheeteditormodel.hpp"
 
-#include "commands/flipcommand.hpp"
+#include "commands/movesubsheetcommand.hpp"
 
 namespace nostalgia::gfx {
 
@@ -139,11 +140,15 @@ size_t TileSheetEditorModel::palettePage() const noexcept {
 	return m_palettePage;
 }
 
-void TileSheetEditorModel::drawCommand(ox::Point const&pt, std::size_t const palIdx) noexcept {
+void TileSheetEditorModel::drawCommand(ox::Point const &pt, std::size_t const palIdx) noexcept {
+	if (m_lastDrawUpdatePt == pt) {
+		return;
+	}
 	auto const &activeSubSheet = getSubSheet(m_img, m_activeSubsSheetIdx);
 	if (pt.x >= activeSubSheet.columns * TileWidth || pt.y >= activeSubSheet.rows * TileHeight) {
 		return;
 	}
+	m_lastDrawUpdatePt = pt;
 	auto const idx = gfx::idx(activeSubSheet, pt);
 	if (m_ongoingDrawCommand) {
 		m_updated = m_updated || m_ongoingDrawCommand->append(idx);
@@ -153,6 +158,26 @@ void TileSheetEditorModel::drawCommand(ox::Point const&pt, std::size_t const pal
 	}
 }
 
+void TileSheetEditorModel::drawLineCommand(ox::Point const &pt, std::size_t const palIdx) noexcept {
+	if (m_lastDrawUpdatePt == pt) {
+		return;
+	}
+	auto const &activeSubSheet = getSubSheet(m_img, m_activeSubsSheetIdx);
+	if (pt.x >= activeSubSheet.columns * TileWidth || pt.y >= activeSubSheet.rows * TileHeight) {
+		return;
+	}
+	m_lastDrawUpdatePt = pt;
+	auto const idx = gfx::idx(activeSubSheet, pt);
+	if (m_ongoingDrawCommand) {
+		m_ongoingDrawCommand->lineUpdate(m_lineStartPt, pt);
+		m_updated = true;
+	} else if (getPixel(activeSubSheet, idx) != palIdx) {
+		std::ignore = pushCommand(ox::make<DrawCommand>(
+			m_img, m_activeSubsSheetIdx, idx, static_cast<int>(palIdx)));
+		m_lineStartPt = pt;
+	}
+}
+
 void TileSheetEditorModel::endDrawCommand() noexcept {
 	m_ongoingDrawCommand = nullptr;
 }
@@ -303,6 +328,10 @@ ox::Error TileSheetEditorModel::flipY() noexcept {
 	return pushCommand(ox::make<FlipYCommand>(m_img, m_activeSubsSheetIdx, a, b));
 }
 
+ox::Error TileSheetEditorModel::moveSubSheet(TileSheet::SubSheetIdx src, TileSheet::SubSheetIdx dst) noexcept {
+	return pushCommand(ox::make<MoveSubSheetCommand>(m_img, std::move(src), std::move(dst)));
+}
+
 void TileSheetEditorModel::getFillPixels(
 		TileSheet::SubSheet const&activeSubSheet,
 		ox::Span<bool> pixels,
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.hpp
index 9af2ec86..95cab4f4 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditormodel.hpp
@@ -34,6 +34,8 @@ class TileSheetEditorModel: public ox::SignalHandler {
 		class DrawCommand *m_ongoingDrawCommand = nullptr;
 		studio::SelectionTracker m_selTracker;
 		ox::Optional<studio::Selection> m_selection;
+		ox::Point m_lineStartPt;
+		ox::Point m_lastDrawUpdatePt;
 		bool m_updated = false;
 
 	public:
@@ -71,6 +73,8 @@ class TileSheetEditorModel: public ox::SignalHandler {
 
 		void drawCommand(ox::Point const&pt, std::size_t palIdx) noexcept;
 
+		void drawLineCommand(ox::Point const&pt, std::size_t palIdx) noexcept;
+
 		void endDrawCommand() noexcept;
 
 		void addSubsheet(TileSheet::SubSheetIdx const&parentIdx) noexcept;
@@ -130,6 +134,8 @@ class TileSheetEditorModel: public ox::SignalHandler {
 
 		ox::Error flipY() noexcept;
 
+		ox::Error moveSubSheet(TileSheet::SubSheetIdx src, TileSheet::SubSheetIdx dst) noexcept;
+
 	private:
 		void getFillPixels(
 			TileSheet::SubSheet const&activeSubSheet,
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.cpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.cpp
index 03fdaee6..0776a9a8 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.cpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.cpp
@@ -11,7 +11,8 @@
 
 namespace nostalgia::gfx {
 
-TileSheetEditorView::TileSheetEditorView(studio::StudioContext &sctx, ox::StringView path, studio::UndoStack &undoStack):
+TileSheetEditorView::TileSheetEditorView(
+		studio::StudioContext &sctx, ox::StringViewCR path, studio::UndoStack &undoStack):
 	m_model(sctx, path, undoStack),
 	m_pixelsDrawer(m_model) {
 	glBindVertexArray(0);
@@ -76,6 +77,11 @@ void TileSheetEditorView::clickDraw(ox::Vec2 const&paneSize, ox::Vec2 const&clic
 	m_model.drawCommand(pt, m_palIdx);
 }
 
+void TileSheetEditorView::clickLine(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept {
+	auto const pt = clickPoint(paneSize, clickPos);
+	m_model.drawLineCommand(pt, m_palIdx);
+}
+
 void TileSheetEditorView::clickSelect(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept {
 	auto const pt = clickPoint(paneSize, clickPos);
 	m_model.select(pt);
@@ -90,6 +96,7 @@ void TileSheetEditorView::releaseMouseButton(TileSheetTool tool) noexcept {
 	switch (tool) {
 		case TileSheetTool::Draw:
 		case TileSheetTool::Fill:
+		case TileSheetTool::Line:
 			m_model.endDrawCommand();
 			break;
 		case TileSheetTool::Select:
diff --git a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.hpp b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.hpp
index a3198151..b0dbab27 100644
--- a/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.hpp
+++ b/src/nostalgia/modules/gfx/src/studio/tilesheeteditor/tilesheeteditorview.hpp
@@ -23,6 +23,7 @@ enum class TileSheetTool {
 	Select,
 	Draw,
 	Fill,
+	Line,
 };
 
 [[nodiscard]]
@@ -34,6 +35,8 @@ constexpr auto toString(TileSheetTool t) noexcept {
 			return "Draw";
 		case TileSheetTool::Fill:
 			return "Fill";
+		case TileSheetTool::Line:
+			return "Line";
 		case TileSheetTool::None:
 			return "None";
 	}
@@ -53,7 +56,7 @@ class TileSheetEditorView: public ox::SignalHandler {
 		std::size_t m_palIdx = 0;
 
 	public:
-		TileSheetEditorView(studio::StudioContext &sctx, ox::StringView path, studio::UndoStack &undoStack);
+		TileSheetEditorView(studio::StudioContext &sctx, ox::StringViewCR path, studio::UndoStack &undoStack);
 
 		~TileSheetEditorView() override = default;
 
@@ -65,6 +68,8 @@ class TileSheetEditorView: public ox::SignalHandler {
 
 		void clickDraw(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept;
 
+		void clickLine(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept;
+
 		void clickSelect(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept;
 
 		void clickFill(ox::Vec2 const&paneSize, ox::Vec2 const&clickPos) noexcept;
diff --git a/src/nostalgia/modules/gfx/src/tilesheet.cpp b/src/nostalgia/modules/gfx/src/tilesheet.cpp
index 078da34a..fb4cc4e8 100644
--- a/src/nostalgia/modules/gfx/src/tilesheet.cpp
+++ b/src/nostalgia/modules/gfx/src/tilesheet.cpp
@@ -177,7 +177,7 @@ TileSheet::SubSheetIdx validateSubSheetIdx(
 			pIdx.resize(pIdxIt);
 			return std::move(pIdx);
 		} else {
-			currentIdx = pSubsheet.subsheets.size() - 1;
+			currentIdx = static_cast<uint32_t>(pSubsheet.subsheets.size() - 1);
 		}
 	}
 	return validateSubSheetIdx(std::move(pIdx), pIdxIt + 1, pSubsheet.subsheets[currentIdx]);
@@ -188,9 +188,9 @@ TileSheet::SubSheetIdx validateSubSheetIdx(TileSheet const&ts, TileSheet::SubShe
 }
 
 TileSheet::SubSheet const&getSubSheet(
-		TileSheet::SubSheetIdx const&idx,
+		ox::SpanView<uint32_t> const &idx,
 		std::size_t const idxIt,
-		TileSheet::SubSheet const&pSubsheet) noexcept {
+		TileSheet::SubSheet const &pSubsheet) noexcept {
 	if (idxIt == idx.size()) {
 		return pSubsheet;
 	}
@@ -202,7 +202,7 @@ TileSheet::SubSheet const&getSubSheet(
 }
 
 TileSheet::SubSheet &getSubSheet(
-		TileSheet::SubSheetIdx const&idx,
+		ox::SpanView<uint32_t> const &idx,
 		std::size_t const idxIt,
 		TileSheet::SubSheet &pSubsheet) noexcept {
 	if (idxIt == idx.size()) {
@@ -211,11 +211,11 @@ TileSheet::SubSheet &getSubSheet(
 	return getSubSheet(idx, idxIt + 1, pSubsheet.subsheets[idx[idxIt]]);
 }
 
-TileSheet::SubSheet const&getSubSheet(TileSheet const&ts, TileSheet::SubSheetIdx const&idx) noexcept {
+TileSheet::SubSheet const&getSubSheet(TileSheet const &ts, ox::SpanView<uint32_t> const &idx) noexcept {
 	return gfx::getSubSheet(idx, 0, ts.subsheet);
 }
 
-TileSheet::SubSheet &getSubSheet(TileSheet &ts, TileSheet::SubSheetIdx const&idx) noexcept {
+TileSheet::SubSheet &getSubSheet(TileSheet &ts, ox::SpanView<uint32_t> const&idx) noexcept {
 	return gfx::getSubSheet(idx, 0, ts.subsheet);
 }
 
@@ -227,7 +227,20 @@ ox::Error addSubSheet(TileSheet &ts, TileSheet::SubSheetIdx const&idx) noexcept
 		parent.subsheets.emplace_back(++ts.idIt, "Subsheet 0", parent.columns, parent.rows);
 		parent.subsheets.emplace_back(++ts.idIt, "Subsheet 1", 1, 1);
 	}
-	return ox::Error(0);
+	return {};
+}
+
+ox::Error insertSubSheet(TileSheet &ts, ox::SpanView<uint32_t> const&idx, TileSheet::SubSheet ss) noexcept {
+	if (idx.empty()) {
+		return ox::Error{1, "invalid insert idx"};
+	}
+	auto &parent = getSubSheet(ts, {idx.data(), idx.size() - 1});
+	auto const insertIdx = idx[idx.size() - 1];
+	if (insertIdx > parent.subsheets.size()) {
+		return ox::Error{1, "invalid insert idx"};
+	}
+	parent.subsheets.emplace(insertIdx, std::move(ss));
+	return {};
 }
 
 ox::Error rmSubSheet(
diff --git a/src/olympic/keel/include/keel/assetmanager.hpp b/src/olympic/keel/include/keel/assetmanager.hpp
index 364f26f2..0730e62e 100644
--- a/src/olympic/keel/include/keel/assetmanager.hpp
+++ b/src/olympic/keel/include/keel/assetmanager.hpp
@@ -295,7 +295,9 @@ class AssetManager {
 		}
 
 		ox::Error reloadAsset(ox::StringViewCR assetId) noexcept {
-			m_fileUpdated[assetId]->emit(assetId);
+			if (m_fileUpdated.contains(assetId)) {
+				m_fileUpdated[assetId]->emit(assetId);
+			}
 			return {};
 		}
 
diff --git a/src/olympic/studio/applib/src/projectexplorer.cpp b/src/olympic/studio/applib/src/projectexplorer.cpp
index f0edd82a..20ba0dfa 100644
--- a/src/olympic/studio/applib/src/projectexplorer.cpp
+++ b/src/olympic/studio/applib/src/projectexplorer.cpp
@@ -47,17 +47,17 @@ void ProjectExplorer::fileContextMenu(ox::StringViewCR path) const noexcept {
 }
 
 void ProjectExplorer::dirContextMenu(ox::StringViewCR path) const noexcept {
-    if (ImGui::BeginPopupContextItem("DirMenu", ImGuiPopupFlags_MouseButtonRight)) {
-        if (ImGui::MenuItem("Add Item")) {
-            addItem.emit(path);
-        }
-        if (ImGui::MenuItem("Add Directory")) {
-            addDir.emit(path);
-        }
-		if (ImGui::MenuItem("Delete")) {
+	if (ImGui::BeginPopupContextItem("DirMenu", ImGuiPopupFlags_MouseButtonRight)) {
+		if (ImGui::MenuItem("Add Item")) {
+			addItem.emit(path);
+		}
+		if (ImGui::MenuItem("Add Directory")) {
+			addDir.emit(path);
+		}
+		if (path.len() && ImGui::MenuItem("Delete")) {
 			deleteItem.emit(path);
 		}
-        ImGui::EndPopup();
+		ImGui::EndPopup();
     }
 }
 
diff --git a/src/olympic/studio/applib/src/renamefile.cpp b/src/olympic/studio/applib/src/renamefile.cpp
index b4c633c7..73a2ff19 100644
--- a/src/olympic/studio/applib/src/renamefile.cpp
+++ b/src/olympic/studio/applib/src/renamefile.cpp
@@ -41,18 +41,35 @@ void RenameFile::draw(StudioContext &ctx) noexcept {
 		case Stage::Opening:
 			ImGui::OpenPopup(title().c_str());
 			m_open = true;
+			m_fileExists = false;
 			m_stage = Stage::Open;
 		[[fallthrough]];
 		case Stage::Open:
 			setSize({250, 0});
-			drawWindow(ctx.tctx, m_open, [this] {
+			drawWindow(ctx.tctx, m_open, [this, &ctx] {
 				if (ImGui::IsWindowAppearing()) {
 					ImGui::SetKeyboardFocusHere();
 				}
-				ig::InputText("Name", m_name);
-				ImGui::Text("%s%s", m_path.c_str(), m_name.c_str());
-				if (ig::PopupControlsOkCancel(m_open) == ig::PopupResponse::OK) {
-					moveFile.emit(m_oldPath, m_path + m_name);
+				m_fileExists = !ig::InputText("Name", m_name) && m_fileExists;
+				auto const nameInputFocused = ImGui::IsItemFocused();
+				if (m_fileExists) {
+					ImGui::Text("File %s already exists.", m_name.c_str());
+				} else {
+					ImGui::Text("%s%s", m_path.c_str(), m_name.c_str());
+				}
+				bool b{};
+				auto const response = ig::PopupControlsOkCancel(b);
+				if (response == ig::PopupResponse::OK ||
+				    (nameInputFocused && ImGui::IsKeyPressed(ImGuiKey_Enter))) {
+					auto const newPath = m_path + m_name;
+					if (!ctx.project->exists(newPath)) {
+						moveFile.emit(m_oldPath, newPath);
+						close();
+					} else {
+						m_open = true;
+						m_fileExists = true;
+					}
+				} else if (response == ig::PopupResponse::Cancel) {
 					close();
 				}
 			});
diff --git a/src/olympic/studio/applib/src/renamefile.hpp b/src/olympic/studio/applib/src/renamefile.hpp
index 2af0326d..4625118f 100644
--- a/src/olympic/studio/applib/src/renamefile.hpp
+++ b/src/olympic/studio/applib/src/renamefile.hpp
@@ -21,6 +21,7 @@ class RenameFile: public Popup {
 		ox::String m_oldPath;
 		ox::String m_path;
 		ox::IString<255> m_name;
+		bool m_fileExists{};
 		bool m_open{};
 
 	public:
diff --git a/src/olympic/studio/applib/src/studioapp.cpp b/src/olympic/studio/applib/src/studioapp.cpp
index 64c6ba89..3cbe35a9 100644
--- a/src/olympic/studio/applib/src/studioapp.cpp
+++ b/src/olympic/studio/applib/src/studioapp.cpp
@@ -349,10 +349,6 @@ void StudioUI::handleKeyInput() noexcept {
 						m_activeEditorUpdatePending = m_activeEditor;
 					}
 				}
-				if (ImGui::IsKeyPressed(ImGuiKey_0)) {
-					m_activeEditor = m_editors[10 < m_editors.size() ? 10 : range].get();
-					m_activeEditorUpdatePending = m_activeEditor;
-				}
 			}
 		}
 	}
@@ -396,6 +392,18 @@ ox::Error StudioUI::handleMoveFile(ox::StringViewCR oldPath, ox::StringViewCR ne
 	return m_projectExplorer.refreshProjectTreeModel();
 }
 
+ox::Error StudioUI::handleDeleteFile(ox::StringViewCR path) noexcept {
+	for (size_t i{}; auto &e : m_editors) {
+		if (path == e->itemPath()) {
+			oxLogError(m_editors.erase(i).error);
+			oxLogError(closeFile(path));
+			break;
+		}
+		++i;
+	}
+	return m_projectExplorer.refreshProjectTreeModel();
+}
+
 ox::Error StudioUI::createOpenProject(ox::StringViewCR path) noexcept {
 	std::error_code ec;
 	std::filesystem::create_directories(toStdStringView(path), ec);
@@ -416,7 +424,7 @@ ox::Error StudioUI::openProjectPath(ox::StringParam path) noexcept {
 	m_newDirDialog.newDir.connect(m_sctx.project, &Project::mkdir);
 	m_project->dirAdded.connect(&m_projectExplorer, &ProjectExplorer::refreshProjectTreeModel);
 	m_project->fileAdded.connect(&m_projectExplorer, &ProjectExplorer::refreshProjectTreeModel);
-	m_project->fileDeleted.connect(&m_projectExplorer, &ProjectExplorer::refreshProjectTreeModel);
+	m_project->fileDeleted.connect(this, &StudioUI::handleDeleteFile);
 	m_project->fileMoved.connect(this, &StudioUI::handleMoveFile);
 	m_openFiles.clear();
 	m_editors.clear();
@@ -499,11 +507,15 @@ ox::Error StudioUI::queueFileMove(ox::StringParam src, ox::StringParam dst) noex
 
 void StudioUI::procFileMoves() noexcept {
 	for (auto const &m : m_queuedMoves) {
-		oxLogError(m_project->moveItem(m.a, m.b));
+		if (!m_project->exists(m.b)) {
+			oxLogError(m_project->moveItem(m.a, m.b));
+		}
 	}
 	m_queuedMoves.clear();
 	for (auto const &m : m_queuedDirMoves) {
-		oxLogError(m_project->moveDir(m.a, m.b));
+		if (!m_project->exists(m.b)) {
+			oxLogError(m_project->moveDir(m.a, m.b));
+		}
 	}
 	m_queuedDirMoves.clear();
 }
diff --git a/src/olympic/studio/applib/src/studioapp.hpp b/src/olympic/studio/applib/src/studioapp.hpp
index c2e6eb32..6dfc730f 100644
--- a/src/olympic/studio/applib/src/studioapp.hpp
+++ b/src/olympic/studio/applib/src/studioapp.hpp
@@ -104,6 +104,8 @@ class StudioUI: public ox::SignalHandler {
 
 		ox::Error handleMoveFile(ox::StringViewCR oldPath, ox::StringViewCR newPath, ox::UUID const&id) noexcept;
 
+		ox::Error handleDeleteFile(ox::StringViewCR path) noexcept;
+
 		ox::Error createOpenProject(ox::StringViewCR path) noexcept;
 
 		ox::Error openProjectPath(ox::StringParam path) noexcept;
diff --git a/src/olympic/studio/modlib/src/filetreemodel.cpp b/src/olympic/studio/modlib/src/filetreemodel.cpp
index d7d347a0..9a364b25 100644
--- a/src/olympic/studio/modlib/src/filetreemodel.cpp
+++ b/src/olympic/studio/modlib/src/filetreemodel.cpp
@@ -88,7 +88,7 @@ FileTreeModel::FileTreeModel(
 void FileTreeModel::draw(turbine::Context &tctx) const noexcept {
 	constexpr auto dirFlags = ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick;
 	auto const selected = m_explorer.selected(this) ? ImGuiTreeNodeFlags_Selected : 0;
-	if (!m_children.empty()) {
+	if (m_fileType == ox::FileType::Directory) {
 		auto const nodeOpen = ImGui::TreeNodeEx(m_name.c_str(), dirFlags | selected);
 		if (ImGui::IsItemActivated() || ImGui::IsItemClicked(1)) {
 			m_explorer.setSelectedNode(this);
@@ -104,7 +104,8 @@ void FileTreeModel::draw(turbine::Context &tctx) const noexcept {
 		if (ig::DragDropTarget const dragDropTarget; dragDropTarget) {
 			auto const [ref, err] = ig::getDragDropPayload<FileRef>("FileRef");
 			if (!err) {
-				auto const name = substr(ref.path, find(ref.path.rbegin(), ref.path.rend(), '/').offset() + 1);
+				auto const name = substr(
+					ref.path, find(ref.path.rbegin(), ref.path.rend(), '/').offset() + 1);
 				if (ref.isDir) {
 					m_explorer.dirMoved(ref.path, sfmt("{}/{}", m_fullPath, name));
 				} else {
diff --git a/src/olympic/studio/modlib/src/imguiutil.cpp b/src/olympic/studio/modlib/src/imguiutil.cpp
index d3af2aaf..12549785 100644
--- a/src/olympic/studio/modlib/src/imguiutil.cpp
+++ b/src/olympic/studio/modlib/src/imguiutil.cpp
@@ -64,13 +64,11 @@ PopupResponse PopupControlsOkCancel(
 	ImGui::Separator();
 	ImGui::SetCursorPosX(popupWidth - 118);
 	if (ImGui::Button(ok.c_str(), btnSz)) {
-		ImGui::CloseCurrentPopup();
 		popupOpen = false;
 		out = PopupResponse::OK;
 	}
 	ImGui::SameLine();
 	if (ImGui::IsKeyDown(ImGuiKey_Escape) || ImGui::Button(cancel.c_str(), btnSz)) {
-		ImGui::CloseCurrentPopup();
 		popupOpen = false;
 		out = PopupResponse::Cancel;
 	}
diff --git a/src/olympic/studio/modlib/src/project.cpp b/src/olympic/studio/modlib/src/project.cpp
index 1aa311a0..dbf34dbb 100644
--- a/src/olympic/studio/modlib/src/project.cpp
+++ b/src/olympic/studio/modlib/src/project.cpp
@@ -46,6 +46,13 @@ static ox::Result<ox::Vector<ox::String>> listAllRecursive(ox::FileSystem &fs, o
 	return std::move(out);
 }
 
+[[nodiscard]]
+static constexpr bool isParentOf(ox::StringViewCR parent, ox::StringViewCR child) noexcept {
+	if (endsWith(child, "/")) {
+		return beginsWith(child, parent);
+	}
+	return beginsWith(sfmt("{}/", child), parent);
+}
 
 Project::Project(keel::Context &ctx, ox::String path, ox::StringViewCR projectDataDir):
 	m_kctx(ctx),
@@ -99,6 +106,9 @@ ox::Error Project::moveItem(ox::StringViewCR src, ox::StringViewCR dest) noexcep
 }
 
 ox::Error Project::moveDir(ox::StringViewCR src, ox::StringViewCR dest) noexcept {
+	if (isParentOf(src, dest)) {
+		return ox::Error{1, "cannot move parent to a child directory"};
+	}
 	OX_REQUIRE(files, listAllRecursive(m_fs, src));
 	OX_RETURN_ERROR(m_fs.move(src, dest));
 	fileMoved.emit(src, dest, ox::UUID{});