diff --git a/src/filesystem/filesystem.c b/src/filesystem/filesystem.c
new file mode 100644
index 00000000..f9a2718e
--- /dev/null
+++ b/src/filesystem/filesystem.c
@@ -0,0 +1,36 @@
+#include "filesystem.h"
+#include "../util.h"
+#include <physfs.h>
+#ifdef APPLE
+#include <mach-o/dyld.h>
+#endif
+
+void lovrFilesystemInit(const char* arg0) {
+  if (!PHYSFS_init(arg0)) {
+    error("Could not initialize filesystem: %s", PHYSFS_getLastError());
+  }
+}
+
+void lovrFilesystemDestroy() {
+  PHYSFS_deinit();
+}
+
+int lovrFilesystemExists(const char* path) {
+  return PHYSFS_exists(path);
+}
+
+const char* lovrFilesystemGetExecutablePath() {
+#ifdef APPLE
+  char path[1024];
+  uint32_t size = sizeof(path);
+  if (_NSGetExecutablePath(path, &size) == 0) {
+    return path;
+  }
+#endif
+
+  return NULL;
+}
+
+int lovrFilesystemSetSource(const char* source) {
+  return PHYSFS_mount(source, NULL, 0);
+}
diff --git a/src/filesystem/filesystem.h b/src/filesystem/filesystem.h
new file mode 100644
index 00000000..4e67c317
--- /dev/null
+++ b/src/filesystem/filesystem.h
@@ -0,0 +1,5 @@
+void lovrFilesystemInit(const char* arg0);
+void lovrFilesystemDestroy();
+int lovrFilesystemExists(const char* path);
+const char* lovrFilesystemGetExecutablePath();
+int lovrFilesystemSetSource(const char* source);
diff --git a/src/lovr.c b/src/lovr.c
index 9499a1a0..fbc40898 100644
--- a/src/lovr.c
+++ b/src/lovr.c
@@ -3,11 +3,28 @@
 #include <stdlib.h>
 
 #include "lovr/event.h"
+#include "lovr/filesystem.h"
 #include "lovr/graphics.h"
 #include "lovr/headset.h"
 #include "lovr/timer.h"
 
-void lovrInit(lua_State* L) {
+void lovrInit(lua_State* L, int argc, char** argv) {
+
+  // arg global
+  lua_newtable(L);
+  if (argc > 0) {
+    lua_pushstring(L, argv[0]);
+    lua_rawseti(L, -2, -2);
+  }
+
+  lua_pushstring(L, "lovr");
+  lua_rawseti(L, -2, -1);
+  for (int i = 1; i < argc; i++) {
+    lua_pushstring(L, argv[i]);
+    lua_rawseti(L, -2, i);
+  }
+
+  lua_setglobal(L, "arg");
 
   // lovr = {}
   lua_newtable(L);
@@ -15,12 +32,13 @@ void lovrInit(lua_State* L) {
 
   // Preload modules
   luaPreloadModule(L, "lovr.event", l_lovrEventInit);
+  luaPreloadModule(L, "lovr.filesystem", l_lovrFilesystemInit);
   luaPreloadModule(L, "lovr.graphics", l_lovrGraphicsInit);
   luaPreloadModule(L, "lovr.headset", l_lovrHeadsetInit);
   luaPreloadModule(L, "lovr.timer", l_lovrTimerInit);
 
   // Bootstrap
-  char buffer[1024];
+  char buffer[2048];
   snprintf(buffer, sizeof(buffer), "%s",
     "local conf = { "
     "  modules = { "
@@ -31,6 +49,12 @@ void lovrInit(lua_State* L) {
     "  } "
     "} "
 
+    "lovr.filesystem = require('lovr.filesystem') "
+    "lovr.filesystem.init(arg[-2]) "
+    "if not lovr.filesystem.setSource(lovr.filesystem.getExecutablePath()) then "
+    "  lovr.filesystem.setSource(arg[1] or '.') "
+    "end "
+
     "local success, err = pcall(require, 'conf') "
     "if lovr.conf then "
     "  success, err = pcall(lovr.conf, conf) "
@@ -76,18 +100,10 @@ void lovrDestroy(int exitCode) {
   exit(exitCode);
 }
 
-void lovrRun(lua_State* L, char* root) {
-
-  // Construct path to main.lua based on command line argument
-  char path[512];
-  if (root) {
-    snprintf(path, sizeof(path), "%s/main.lua", root);
-  } else {
-    snprintf(path, sizeof(path), "main.lua");
-  }
+void lovrRun(lua_State* L) {
 
   // Run "main.lua" which will override/define pieces of lovr
-  if (fileExists(path) && luaL_dofile(L, path)) {
+  if (fileExists("main.lua") && luaL_dofile(L, "main.lua")) {
     lovrOnLuaError(L);
     exit(EXIT_FAILURE);
   }
diff --git a/src/lovr.h b/src/lovr.h
index 68a45c94..cda2e8cc 100644
--- a/src/lovr.h
+++ b/src/lovr.h
@@ -3,9 +3,9 @@
 #include <lualib.h>
 #include "glfw.h"
 
-void lovrInit(lua_State* L);
+void lovrInit(lua_State* L, int argc, char** argv);
 void lovrDestroy(int exitCode);
-void lovrRun(lua_State* L, char* mainPath);
+void lovrRun(lua_State* L);
 int lovrOnLuaError(lua_State* L);
 void lovrOnGlfwError(int code, const char* description);
 void lovrOnClose(GLFWwindow* window);
diff --git a/src/lovr/filesystem.c b/src/lovr/filesystem.c
new file mode 100644
index 00000000..8ae7ea48
--- /dev/null
+++ b/src/lovr/filesystem.c
@@ -0,0 +1,52 @@
+#include "filesystem.h"
+#include "../filesystem/filesystem.h"
+
+const luaL_Reg lovrFilesystem[] = {
+  { "exists", l_lovrFilesystemExists },
+  { "getExecutablePath", l_lovrFilesystemGetExecutablePath },
+  { "init", l_lovrFilesystemInitialize },
+  { "setSource", l_lovrFilesystemSetSource },
+  { NULL, NULL }
+};
+
+int l_lovrFilesystemInit(lua_State* L) {
+  lua_newtable(L);
+  luaL_register(L, NULL, lovrFilesystem);
+  return 1;
+}
+
+int l_lovrFilesystemInitialize(lua_State* L) {
+  const char* arg0 = luaL_checkstring(L, 1);
+  lovrFilesystemInit(arg0);
+  return 0;
+}
+
+int l_lovrFilesystemExists(lua_State* L) {
+  const char* path = luaL_checkstring(L, 1);
+  lua_pushboolean(L, lovrFilesystemExists(path));
+  return 1;
+}
+
+int l_lovrFilesystemGetExecutablePath(lua_State* L) {
+  const char* exePath = lovrFilesystemGetExecutablePath();
+
+  if (exePath) {
+    lua_pushstring(L, exePath);
+  } else {
+    lua_pushnil(L);
+  }
+
+  return 1;
+}
+
+int l_lovrFilesystemSetSource(lua_State* L) {
+  const char* source = lua_tostring(L, 1);
+
+  if (source) {
+    lua_pushboolean(L, lovrFilesystemSetSource(source));
+  } else {
+    lua_pushboolean(L, 0);
+  }
+
+  return 1;
+}
diff --git a/src/lovr/filesystem.h b/src/lovr/filesystem.h
new file mode 100644
index 00000000..17bf76ef
--- /dev/null
+++ b/src/lovr/filesystem.h
@@ -0,0 +1,10 @@
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+extern const luaL_Reg lovrFilesystem[];
+int l_lovrFilesystemInit(lua_State* L);
+int l_lovrFilesystemInitialize(lua_State* L);
+int l_lovrFilesystemExists(lua_State* L);
+int l_lovrFilesystemGetExecutablePath(lua_State* L);
+int l_lovrFilesystemSetSource(lua_State* L);
diff --git a/src/main.c b/src/main.c
index f2704c29..81d21aff 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,8 +6,8 @@ int main(int argc, char** argv) {
   luaL_openlibs(L);
 
   initGlfw(lovrOnGlfwError, lovrOnClose, L);
-  lovrInit(L);
-  lovrRun(L, argc > 1 ? argv[1] : NULL);
+  lovrInit(L, argc, argv);
+  lovrRun(L);
 
   return 0;
 }