diff --git a/include/app/SvgScrew.hpp b/include/app/SvgScrew.hpp
index a0810129..bc577649 100644
--- a/include/app/SvgScrew.hpp
+++ b/include/app/SvgScrew.hpp
@@ -1,5 +1,6 @@
 #pragma once
 #include "common.hpp"
+#include "widget/Widget.hpp"
 #include "widget/FramebufferWidget.hpp"
 #include "widget/SvgWidget.hpp"
 
@@ -9,10 +10,12 @@ namespace app {
 
 
 /** If you don't add these to your ModuleWidget, they will fall out of the rack... */
-struct SvgScrew : widget::FramebufferWidget {
+struct SvgScrew : widget::Widget {
+	widget::FramebufferWidget *fb;
 	widget::SvgWidget *sw;
 
 	SvgScrew();
+	void setSvg(std::shared_ptr<Svg> svg);
 };
 
 
diff --git a/include/common.hpp b/include/common.hpp
index 757f35e4..3c1aa373 100644
--- a/include/common.hpp
+++ b/include/common.hpp
@@ -21,6 +21,7 @@ namespace rack {
 
 /** Deprecation notice for functions
 E.g.
+
 	DEPRECATED void foo();
 */
 #if defined(__GNUC__) || defined(__clang__)
@@ -33,9 +34,12 @@ E.g.
 
 /** Concatenates two literals or two macros
 Example:
+
 	#define COUNT 42
 	CONCAT(myVariable, COUNT)
+
 expands to
+
 	myVariable42
 */
 #define CONCAT_LITERAL(x, y) x ## y
@@ -44,10 +48,14 @@ expands to
 
 /** Surrounds raw text with quotes
 Example:
+
 	#define NAME "world"
 	printf("Hello " TOSTRING(NAME))
+
 expands to
+
 	printf("Hello " "world")
+
 and of course the C++ lexer/parser then concatenates the string literals.
 */
 #define TOSTRING_LITERAL(x) #x
@@ -60,26 +68,35 @@ and of course the C++ lexer/parser then concatenates the string literals.
 
 /** Reserve space for `count` enums starting with `name`.
 Example:
+
 	enum Foo {
 		ENUMS(BAR, 14),
 		BAZ
 	};
 
-	BAR + 0 to BAR + 13 is reserved. BAZ has a value of 14.
+`BAR + 0` to `BAR + 13` is reserved. `BAZ` has a value of 14.
 */
 #define ENUMS(name, count) name, name ## _LAST = name + (count) - 1
 
 
 /** References binary files compiled into the program.
 For example, to include a file "Test.dat" directly into your program binary, add
+
 	BINARIES += Test.dat
+
 to your Makefile and declare
+
 	BINARY(Test_dat);
+
 at the root of a .c or .cpp source file. Note that special characters are replaced with "_". Then use
+
 	BINARY_START(Test_dat)
 	BINARY_END(Test_dat)
+
 to reference the data beginning and end as a void* array, and
+
 	BINARY_SIZE(Test_dat)
+
 to get its size in bytes.
 */
 #if defined ARCH_MAC
@@ -99,14 +116,15 @@ to get its size in bytes.
 
 /** C#-style property constructor
 Example:
+
 	Foo *foo = construct<Foo>(&Foo::greeting, "Hello world", &Foo::legs, 2);
 */
-template<typename T>
+template <typename T>
 T *construct() {
 	return new T;
 }
 
-template<typename T, typename F, typename V, typename... Args>
+template <typename T, typename F, typename V, typename... Args>
 T *construct(F f, V v, Args... args) {
 	T *o = construct<T>(args...);
 	o->*f = v;
@@ -115,21 +133,21 @@ T *construct(F f, V v, Args... args) {
 
 /** Defers code until the scope is destructed
 From http://www.gingerbill.org/article/defer-in-cpp.html
-
 Example:
+
 	file = fopen(...);
 	DEFER({
 		fclose(file);
 	});
 */
-template<typename F>
+template <typename F>
 struct DeferWrapper {
 	F f;
 	DeferWrapper(F f) : f(f) {}
 	~DeferWrapper() { f(); }
 };
 
-template<typename F>
+template <typename F>
 DeferWrapper<F> deferWrapper(F f) {
 	return DeferWrapper<F>(f);
 }
@@ -137,7 +155,7 @@ DeferWrapper<F> deferWrapper(F f) {
 #define DEFER(code) auto CONCAT(_defer_, __COUNTER__) = rack::deferWrapper([&]() code)
 
 
-/** Reports a string to the user */
+/** An exception meant to be shown to the user */
 struct UserException : std::runtime_error {
 	UserException(const std::string &msg) : std::runtime_error(msg) {}
 };
diff --git a/include/componentlibrary.hpp b/include/componentlibrary.hpp
index 3c712a2d..e7166a8b 100644
--- a/include/componentlibrary.hpp
+++ b/include/componentlibrary.hpp
@@ -300,9 +300,12 @@ struct SynthTechAlco : app::SvgKnob {
 		minAngle = -0.82*M_PI;
 		maxAngle = 0.82*M_PI;
 		setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/SynthTechAlco.svg")));
+		// Add cap
+		widget::FramebufferWidget *capFb = new widget::FramebufferWidget;
 		widget::SvgWidget *cap = new widget::SvgWidget;
 		cap->setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/SynthTechAlco_cap.svg")));
-		addChild(cap);
+		capFb->addChild(cap);
+		addChild(capFb);
 	}
 };
 
@@ -460,15 +463,6 @@ struct RedGreenBlueLight : GrayModuleLightWidget {
 	}
 };
 
-struct RGBLight : app::ModuleLightWidget {
-	RGBLight() {
-		addBaseColor(nvgRGBf(1, 0, 0));
-		addBaseColor(nvgRGBf(0, 1, 0));
-		addBaseColor(nvgRGBf(0, 0, 1));
-	}
-};
-
-
 /** Based on the size of 5mm LEDs */
 template <typename BASE>
 struct LargeLight : BASE {
@@ -501,7 +495,7 @@ struct TinyLight : BASE {
 	}
 };
 
-/** A light to displayed over PB61303. Must add a color by subclassing or templating. */
+/** A light for displaying on top of PB61303. Must add a color by subclassing or templating. */
 template <typename BASE>
 struct LEDBezelLight : BASE {
 	LEDBezelLight() {
@@ -608,15 +602,13 @@ struct PB61303 : app::SvgSwitch {
 
 struct ScrewSilver : app::SvgScrew {
 	ScrewSilver() {
-		sw->setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/ScrewSilver.svg")));
-		box.size = sw->box.size;
+		setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/ScrewSilver.svg")));
 	}
 };
 
 struct ScrewBlack : app::SvgScrew {
 	ScrewBlack() {
-		sw->setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/ScrewBlack.svg")));
-		box.size = sw->box.size;
+		setSvg(APP->window->loadSvg(asset::system("res/ComponentLibrary/ScrewBlack.svg")));
 	}
 };
 
diff --git a/include/event.hpp b/include/event.hpp
index 6ce81894..f8953dcb 100644
--- a/include/event.hpp
+++ b/include/event.hpp
@@ -5,6 +5,28 @@
 #include <set>
 
 
+
+/** Remaps Ctrl to Cmd on Mac
+Use this instead of GLFW_MOD_CONTROL, since Cmd should be used on Mac in place of Ctrl on Linux/Windows.
+*/
+#if defined ARCH_MAC
+	#define RACK_MOD_CTRL GLFW_MOD_SUPER
+	#define RACK_MOD_CTRL_NAME "Cmd"
+#else
+	#define RACK_MOD_CTRL GLFW_MOD_CONTROL
+	#define RACK_MOD_CTRL_NAME "Ctrl"
+#endif
+#define RACK_MOD_SHIFT_NAME "Shift"
+#define RACK_MOD_ALT_NAME "Alt"
+
+/** Filters actual mod keys from the mod flags.
+Use this if you don't care about GLFW_MOD_CAPS_LOCK and GLFW_MOD_NUM_LOCK.
+Example usage:
+	if ((e.mod & RACK_MOD_MASK) == (RACK_MOD_CTRL | GLFW_MOD_SHIFT)) ...
+*/
+#define RACK_MOD_MASK (GLFW_MOD_SHIFT | GLFW_MOD_CONTROL | GLFW_MOD_ALT | GLFW_MOD_SUPER)
+
+
 namespace rack {
 
 
diff --git a/include/helpers.hpp b/include/helpers.hpp
index 057695d5..574bff47 100644
--- a/include/helpers.hpp
+++ b/include/helpers.hpp
@@ -52,8 +52,8 @@ TWidget *createWidget(math::Vec pos) {
 
 template <class TWidget>
 TWidget *createWidgetCentered(math::Vec pos) {
-	TWidget *o = new TWidget;
-	o->box.pos = pos.minus(o->box.size.div(2));;
+	TWidget *o = createWidget<TWidget>(pos);
+	o->box.pos = o->box.pos.minus(o->box.size.div(2));
 	return o;
 }
 
diff --git a/include/logger.hpp b/include/logger.hpp
index f77ff97f..e35cc12f 100644
--- a/include/logger.hpp
+++ b/include/logger.hpp
@@ -2,14 +2,17 @@
 
 
 /** Example usage:
+
 	DEBUG("error: %d", errno);
+
 will print something like
+
 	[0.123 debug myfile.cpp:45] error: 67
 */
-#define DEBUG(format, ...) rack::logger::log(rack::logger::DEBUG_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
-#define INFO(format, ...) rack::logger::log(rack::logger::INFO_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
-#define WARN(format, ...) rack::logger::log(rack::logger::WARN_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
-#define FATAL(format, ...) rack::logger::log(rack::logger::FATAL_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
+#define DEBUG(format, ...) logger::log(rack::logger::DEBUG_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
+#define INFO(format, ...) logger::log(rack::logger::INFO_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
+#define WARN(format, ...) logger::log(rack::logger::WARN_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
+#define FATAL(format, ...) logger::log(rack::logger::FATAL_LEVEL, __FILE__, __LINE__, format, ##__VA_ARGS__)
 
 
 namespace rack {
@@ -29,8 +32,8 @@ enum Level {
 
 void init();
 void destroy();
-/** Do not use this function directly. Use the macros below.
-Thread-safe.
+/** Do not use this function directly. Use the macros above.
+Thread-safe, meaning messages cannot overlap each other in the log.
 */
 void log(Level level, const char *filename, int line, const char *format, ...);
 
diff --git a/include/rack.hpp b/include/rack.hpp
index fa2cbf82..d681d596 100644
--- a/include/rack.hpp
+++ b/include/rack.hpp
@@ -101,6 +101,7 @@ namespace rack {
 /** Define this macro before including this header to prevent common namespaces from being included in the main `rack::` namespace. */
 #ifndef RACK_FLATTEN_NAMESPACES
 // Import some namespaces for convenience
+using namespace logger;
 using namespace math;
 using namespace widget;
 using namespace ui;
diff --git a/include/string.hpp b/include/string.hpp
index 96cd07e6..a75c9d14 100644
--- a/include/string.hpp
+++ b/include/string.hpp
@@ -13,14 +13,15 @@ namespace string {
 /** Converts a UTF-16/32 string (depending on the size of wchar_t) to a UTF-8 string. */
 std::string fromWstring(const std::wstring &s);
 std::wstring toWstring(const std::string &s);
-/** Converts a `printf()` format string and optional arguments into a std::string
-Remember that "%s" must reference a `char *`, so use `.c_str()` for `std::string`s.
+/** Converts a `printf()` format string and optional arguments into a std::string.
+Remember that "%s" must reference a `char *`, so use `.c_str()` for `std::string`s, otherwise you might get binary garbage.
 */
 std::string f(const char *format, ...);
 /** Replaces all characters to lowercase letters */
 std::string lowercase(const std::string &s);
 /** Replaces all characters to uppercase letters */
 std::string uppercase(const std::string &s);
+/** Removes whitespace from beginning and end of string. */
 std::string trim(const std::string &s);
 /** Truncates and adds "..." to a string, not exceeding `len` characters */
 std::string ellipsize(const std::string &s, size_t len);
diff --git a/include/system.hpp b/include/system.hpp
index ec9dfded..a685b981 100644
--- a/include/system.hpp
+++ b/include/system.hpp
@@ -12,11 +12,13 @@ namespace system {
 
 
 /** Returns a list of all entries (directories, files, symbols) in a directory. */
-std::list<std::string> listEntries(const std::string &path);
+std::list<std::string> getEntries(const std::string &path);
 /** Returns whether the given path is a file. */
 bool isFile(const std::string &path);
 /** Returns whether the given path is a directory. */
 bool isDirectory(const std::string &path);
+/** Moves a file. */
+void moveFile(const std::string &srcPath, const std::string &destPath);
 /** Copies a file. */
 void copyFile(const std::string &srcPath, const std::string &destPath);
 /** Creates a directory.
@@ -36,12 +38,12 @@ Shell injection is possible, so make sure the URL is trusted or hard coded.
 May block, so open in a new thread.
 */
 void openBrowser(const std::string &url);
-/** Opens Explorer, Finder, etc at the folder location. */
+/** Opens Windows Explorer, Finder, etc at the folder location. */
 void openFolder(const std::string &path);
 /** Runs an executable without blocking.
 The launched process will continue running if the current process is closed.
 */
-void runProcessAsync(const std::string &path);
+void runProcessDetached(const std::string &path);
 std::string getOperatingSystemInfo();
 
 
diff --git a/include/window.hpp b/include/window.hpp
index 4a58d70c..8ada93ae 100644
--- a/include/window.hpp
+++ b/include/window.hpp
@@ -14,27 +14,6 @@
 #include <nanosvg.h>
 
 
-/** Remaps Ctrl to Cmd on Mac
-Use this instead of GLFW_MOD_CONTROL, since Cmd should be used on Mac in place of Ctrl on Linux/Windows.
-*/
-#if defined ARCH_MAC
-	#define RACK_MOD_CTRL GLFW_MOD_SUPER
-	#define RACK_MOD_CTRL_NAME "Cmd"
-#else
-	#define RACK_MOD_CTRL GLFW_MOD_CONTROL
-	#define RACK_MOD_CTRL_NAME "Ctrl"
-#endif
-#define RACK_MOD_SHIFT_NAME "Shift"
-#define RACK_MOD_ALT_NAME "Alt"
-
-/** Filters actual mod keys from the mod flags.
-Use this if you don't care about GLFW_MOD_CAPS_LOCK and GLFW_MOD_NUM_LOCK.
-Example usage:
-	if ((e.mod & RACK_MOD_MASK) == (RACK_MOD_CTRL | GLFW_MOD_SHIFT)) ...
-*/
-#define RACK_MOD_MASK (GLFW_MOD_SHIFT | GLFW_MOD_CONTROL | GLFW_MOD_ALT | GLFW_MOD_SUPER)
-
-
 namespace rack {
 
 
diff --git a/src/app/SvgScrew.cpp b/src/app/SvgScrew.cpp
index 5b8bb335..6636e543 100644
--- a/src/app/SvgScrew.cpp
+++ b/src/app/SvgScrew.cpp
@@ -6,8 +6,18 @@ namespace app {
 
 
 SvgScrew::SvgScrew() {
+	fb = new widget::FramebufferWidget;
+	addChild(fb);
+
 	sw = new widget::SvgWidget;
-	addChild(sw);
+	fb->addChild(sw);
+}
+
+
+void SvgScrew::setSvg(std::shared_ptr<Svg> svg) {
+	sw->setSvg(svg);
+	fb->box.size = sw->box.size;
+	box.size = sw->box.size;
 }
 
 
diff --git a/src/patch.cpp b/src/patch.cpp
index 69840655..7a20524f 100644
--- a/src/patch.cpp
+++ b/src/patch.cpp
@@ -91,8 +91,7 @@ void PatchManager::save(std::string path) {
 
 	json_dumpf(rootJ, file, JSON_INDENT(2) | JSON_REAL_PRECISION(9));
 	std::fclose(file);
-	std::remove(path.c_str());
-	std::rename(tmpPath.c_str(), path.c_str());
+	system::moveFile(tmpPath, path);
 }
 
 void PatchManager::saveDialog() {
diff --git a/src/plugin.cpp b/src/plugin.cpp
index 1e6d6e4f..a4295693 100644
--- a/src/plugin.cpp
+++ b/src/plugin.cpp
@@ -149,7 +149,7 @@ static bool loadPlugin(std::string path) {
 	// Search for presets
 	for (Model *model : plugin->models) {
 		std::string presetDir = asset::plugin(plugin, "presets/" + model->slug);
-		for (const std::string &presetPath : system::listEntries(presetDir)) {
+		for (const std::string &presetPath : system::getEntries(presetDir)) {
 			model->presetPaths.push_back(presetPath);
 		}
 	}
@@ -190,7 +190,7 @@ static bool syncUpdate(const Update &update) {
 
 static void loadPlugins(std::string path) {
 	std::string message;
-	for (std::string pluginPath : system::listEntries(path)) {
+	for (std::string pluginPath : system::getEntries(path)) {
 		if (!system::isDirectory(pluginPath))
 			continue;
 		if (!loadPlugin(pluginPath)) {
@@ -271,7 +271,7 @@ static int extractZip(const char *filename, const char *path) {
 static void extractPackages(const std::string &path) {
 	std::string message;
 
-	for (std::string packagePath : system::listEntries(path)) {
+	for (std::string packagePath : system::getEntries(path)) {
 		if (string::filenameExtension(packagePath) != "zip")
 			continue;
 		INFO("Extracting package %s", packagePath.c_str());
diff --git a/src/system.cpp b/src/system.cpp
index 3c7d8cbf..c7cb3f94 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -25,7 +25,7 @@ namespace rack {
 namespace system {
 
 
-std::list<std::string> listEntries(const std::string &path) {
+std::list<std::string> getEntries(const std::string &path) {
 	std::list<std::string> filenames;
 	DIR *dir = opendir(path.c_str());
 	if (dir) {
@@ -56,14 +56,23 @@ bool isDirectory(const std::string &path) {
 	return S_ISDIR(statbuf.st_mode);
 }
 
+void moveFile(const std::string &srcPath, const std::string &destPath) {
+	std::remove(destPath.c_str());
+	// Whether this overwrites existing files is implementation-defined.
+	// i.e. Mingw64 fails to overwrite.
+	// This is why we remove the file above.
+	std::rename(srcPath.c_str(), destPath.c_str());
+}
+
 void copyFile(const std::string &srcPath, const std::string &destPath) {
-	// Open files
+	// Open source
 	FILE *source = fopen(srcPath.c_str(), "rb");
 	if (!source)
 		return;
 	DEFER({
 		fclose(source);
 	});
+	// Open destination
 	FILE *dest = fopen(destPath.c_str(), "wb");
 	if (!dest)
 		return;
@@ -93,7 +102,6 @@ void createDirectory(const std::string &path) {
 }
 
 int getLogicalCoreCount() {
-	// TODO Return the physical cores, not logical cores.
 	return std::thread::hardware_concurrency();
 }
 
@@ -199,7 +207,7 @@ void openFolder(const std::string &path) {
 }
 
 
-void runProcessAsync(const std::string &path) {
+void runProcessDetached(const std::string &path) {
 #if defined ARCH_WIN
 	STARTUPINFOW startupInfo;
 	PROCESS_INFORMATION processInfo;
@@ -212,6 +220,9 @@ void runProcessAsync(const std::string &path) {
 	CreateProcessW(pathW.c_str(), NULL,
 		NULL, NULL, false, 0, NULL, NULL,
 		&startupInfo, &processInfo);
+#else
+	// Not implemented on Linux or Mac
+	assert(0);
 #endif
 }
 
@@ -226,6 +237,7 @@ std::string getOperatingSystemInfo() {
 	ZeroMemory(&info, sizeof(info));
 	info.dwOSVersionInfoSize = sizeof(info);
 	GetVersionExW(&info);
+	// See https://docs.microsoft.com/en-us/windows/desktop/api/winnt/ns-winnt-_osversioninfoa for a list of Windows version numbers.
 	return string::f("Windows %u.%u", info.dwMajorVersion, info.dwMinorVersion);
 #endif
 }