diff --git a/config.ld b/config.ld
new file mode 100644
index 0000000..bbbb391
--- /dev/null
+++ b/config.ld
@@ -0,0 +1 @@
+readme = "README.md"
diff --git a/osx.c b/osx.c
index 25ff3c8..c3c24de 100644
--- a/osx.c
+++ b/osx.c
@@ -6,6 +6,15 @@
  * Author: Lorenzo Cogotti
  */
 
+/**
+ * Operating System eXtension module.
+ *
+ * @license LGPL-3.0-or-later
+ * @copyright 2022, The DoubleFourteen Code Forge
+ * @author Lorenzo Cogotti
+ * @module osx
+ */
+
 #include "xconf.h"
 #include "osx.h"
 #include "osx_dir.h"
@@ -264,19 +273,13 @@ static bool os_dir_filter(lua_State *L, const char *name)
     return result;
 }
 
-static int os_dir_open(lua_State *L)
+static int os_dir_close(lua_State *L)
 {
-    const char *path = luaL_checkstring(L, 1);
+    df_os_dir *dir = todir(L);
 
-    df_os_dir *dir = lua_newuserdata(L, sizeof(*dir));
-
-    dir->hn = os_opendir(path);
-    dir->closeflag = false;
-    if (!dir->hn)
-        return os_pushfail(L, path);
-
-    luaL_setmetatable(L, DF_LUA_DIRHANDLE);
-    return 1;
+    os_closedir(dir->hn);
+    dir->closeflag = true;
+    return 0;
 }
 
 static int os_dir_tostring(lua_State *L)
@@ -299,68 +302,6 @@ static int os_dir_tostring(lua_State *L)
     return 1;
 }
 
-static int os_dir_close(lua_State *L)
-{
-    df_os_dir *dir = todir(L);
-
-    os_closedir(dir->hn);
-    dir->closeflag = true;
-    return 0;
-}
-
-static int os_dir_gc(lua_State *L)
-{
-    df_os_dir *dir = luaL_checkudata(L, 1, DF_LUA_DIRHANDLE);
-
-    if (!dir->closeflag)
-        os_dir_close(L);
-
-    return 0;
-}
-
-static int os_dir_iter(lua_State *L);
-
-static int os_dir(lua_State *L)
-{
-    lua_pushcfunction(L, os_dir_open);
-    lua_pushvalue(L, 1);
-    lua_call(L, 1, 2);
-    if (lua_isnil(L, -2))
-        lua_error(L);
-
-    lua_pop(L, 1);
-
-    lua_pushcclosure(L, os_dir_iter, 2);
-    return 1;
-}
-
-static int os_dir_iter(lua_State *L)
-{
-    const char *path = lua_tostring(L, lua_upvalueindex(1));
-    df_os_dir *dir = lua_touserdata(L, lua_upvalueindex(2));
-    const char *filename;
-
-    errno = 0;
-
-nextfilename:
-    filename = os_readdir(dir->hn);
-    if (!filename) {
-        // Error or end of directory
-        if (errno != 0)
-            luaL_error(L, lua_pushfstring(L, "%s: %s", path, strerror(errno)));
-
-        return 0;
-    }
-
-    // Skip dot and dotdot
-    if (strcmp(filename, ".") == 0 || strcmp(filename, "..") == 0)
-        goto nextfilename;
-
-    // New directory entry
-    lua_pushstring(L, filename);
-    return 1;
-}
-
 static int os_dir_readdir(lua_State *L)
 {
     df_os_dir *dir = todir(L);
@@ -417,6 +358,106 @@ static int os_dir_listfiles(lua_State *L)
     return os_dir_dolistfiles(L, false, NULL);
 }
 
+static int os_dir_gc(lua_State *L)
+{
+    df_os_dir *dir = luaL_checkudata(L, 1, DF_LUA_DIRHANDLE);
+
+    if (!dir->closeflag)
+        os_dir_close(L);
+
+    return 0;
+}
+
+/**
+ * Open a directory.
+ *
+ * @string path path to the directory to be opened
+ * @treturn[1] Dir handle to the newly opened directory
+ * @error[2] error message
+ * @treturn[2] int system error code
+ * @function opendir
+ */
+static int os_dir_open(lua_State *L)
+{
+    const char *path = luaL_checkstring(L, 1);
+
+    df_os_dir *dir = lua_newuserdata(L, sizeof(*dir));
+
+    dir->hn = os_opendir(path);
+    dir->closeflag = false;
+    if (!dir->hn)
+        return os_pushfail(L, path);
+
+    luaL_setmetatable(L, DF_LUA_DIRHANDLE);
+    return 1;
+}
+
+static int os_dir_iter(lua_State *L);
+
+/**
+ * Iterate directory.
+ *
+ * Enumerates directory contents one filename at a time, '.' and '..' are
+ * filtered out. Function is intended to control a for loop.
+ *
+ * @string path path to directory to be traversed
+ * @treturn string next file in directory
+ * @raise error if the directory could not be opened, or an error occurs during its traversal.
+ * @function dir
+ */
+static int os_dir(lua_State *L)
+{
+    lua_pushcfunction(L, os_dir_open);
+    lua_pushvalue(L, 1);
+    lua_call(L, 1, 2);
+    if (lua_isnil(L, -2))
+        lua_error(L);
+
+    lua_pop(L, 1);
+
+    lua_pushcclosure(L, os_dir_iter, 2);
+    return 1;
+}
+
+static int os_dir_iter(lua_State *L)
+{
+    const char *path = lua_tostring(L, lua_upvalueindex(1));
+    df_os_dir *dir = lua_touserdata(L, lua_upvalueindex(2));
+    const char *filename;
+
+    errno = 0;
+
+nextfilename:
+    filename = os_readdir(dir->hn);
+    if (!filename) {
+        // Error or end of directory
+        if (errno != 0)
+            luaL_error(L, lua_pushfstring(L, "%s: %s", path, strerror(errno)));
+
+        return 0;
+    }
+
+    // Skip dot and dotdot
+    if (strcmp(filename, ".") == 0 || strcmp(filename, "..") == 0)
+        goto nextfilename;
+
+    // New directory entry
+    lua_pushstring(L, filename);
+    return 1;
+}
+
+/**
+ * List directory contents.
+ *
+ * @string path path to directory to be listed
+ * @tparam[opt] function filter a function taking a filename string and returning
+ * a boolean to accept/reject each entry
+ * @treturn[1] {string,...} array of filenames within the directory,
+ * excluding '.' and '..'
+ * @error[2] error message
+ * @treturn[2] int system error code
+ * @function listfiles
+ */
 static int os_listfiles(lua_State *L)
 {
     const char *path = luaL_checkstring(L, 1);
@@ -435,6 +476,26 @@ static int os_listfiles(lua_State *L)
     return os_dir_dolistfiles(L, true, path);
 }
 
+/**
+ * File info returned on success by @{stat}.
+ *
+ * @string type file type, either of 'regular', 'directory', or 'other', for
+ * regular files, directories and any other file respectively
+ * @int mtime last modified time in seconds since Unix Epoch, only available for
+ * 'regular' and 'directory'
+ * @int size file size in bytes, only available for 'regular' files
+ * @table FileStat
+ */
+
+/**
+ * Get file info.
+ *
+ * @tparam ?string|File f path or opened file handle
+ * @treturn[1] FileStat on success
+ * @error[2] error message
+ * @treturn[2] int system error code
+ * @function stat
+ */
 static int os_stat(lua_State *L)
 {
     const char *path = NULL;
@@ -471,6 +532,16 @@ static int os_stat(lua_State *L)
     return 1;
 }
 
+/**
+ * Create a new directory.
+ *
+ * @string path path to the directory to be created
+ * @treturn[1] bool true on success and a new directory is created at path
+ * @treturn[2] bool false on failure (note: directory may already exist)
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function mkdir
+ */
 static int os_mkdir(lua_State *L)
 {
     const char *path = luaL_checkstring(L, 1);
@@ -479,6 +550,14 @@ static int os_mkdir(lua_State *L)
     return os_result(L, ec, path);
 }
 
+/**
+ * Get process current working directory.
+ *
+ * @treturn[1] string path to current working directory on success
+ * @error[2] error message
+ * @treturn[2] int system error code
+ * @function getcwd
+ */
 static int os_getcwd(lua_State *L)
 {
 #if LUA_VERSION_NUM >= 502
@@ -542,6 +621,16 @@ fail:
 #endif
 }
 
+/**
+ * Change process current working directory.
+ *
+ * @string path path to the new working directory
+ * @treturn[1] boolean true on success
+ * @treturn[2] boolean false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function chdir
+ */ 
 static int os_chdir(lua_State *L)
 {
     const char *path = luaL_checkstring(L, 1);
@@ -550,6 +639,15 @@ static int os_chdir(lua_State *L)
     return os_result(L, ec, path);
 }
 
+/**
+ * Get the active drive letter.
+ *
+ * @treturn[1] string the current drive letter on systems supporting multiple drives
+ * (e.g. Windows), an empty string otherwise
+ * @error[2] error message
+ * @treturn[2] int system error code
+ * @function getdrive
+ */
 static int os_getdrive(lua_State *L)
 {
     errno = 0;
@@ -569,6 +667,19 @@ static int os_getdrive(lua_State *L)
     return 1;
 }
 
+/**
+ * Change active drive.
+ *
+ * May only succeed on systems with multiple drives (e.g. Windows).
+ * On any other system this function always fail with an appropriate error.
+ *
+ * @string drive new drive letter (e.g. 'A', 'C', 'D')
+ * @treturn[1] bool true on success
+ * @treturn[2] bool false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function chdrive
+ */
 static int os_chdrive(lua_State *L)
 {
     size_t len;
@@ -584,6 +695,22 @@ static int os_chdrive(lua_State *L)
     return os_result(L, ec, NULL);
 }
 
+/**
+ * Set file mode.
+ *
+ * May only succeed on systems where multiple file mode exist (e.g. Windows),
+ * will always fail anywhere else (e.g. Unix).
+ * Typically such error can be ignored.
+ *
+ * @tparam File f a file opened for read
+ * @string mode new mode for file, either of 'binary', 'text', 'u8text',
+ * 'u16text' or 'wtext'
+ * @treturn[1] bool true on success
+ * @treturn[2] bool false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function setmode
+ */
 static int os_setmode(lua_State *L)
 {
     static const char *modes[] = {
@@ -609,6 +736,17 @@ static int os_setmode(lua_State *L)
     return os_result(L, ec, NULL);
 }
 
+/**
+ * Change file size.
+ *
+ * @tparam ?string|File f path or file opened for write
+ * @int size new file size in bytes
+ * @treturn[1] bool true on success
+ * @treturn[2] bool false on failure
+ * @treturn[2] string error string
+ * @treturn[2] int system error code
+ * @function chsize
+ */
 static int os_chsize(lua_State *L)
 {
     lua_Integer size = luaL_checkinteger(L, 2);
@@ -629,6 +767,17 @@ static int os_chsize(lua_State *L)
     return os_result(L, ec, path);
 }
 
+/**
+ * Advise kernel on file access pattern.
+ *
+ * @tparam File f a file opened for read
+ * @string advise read access pattern (either of: 'normal', 'sequential', 'random', 'noreuse')
+ * @treturn[1] boolean true on success
+ * @treturn[2] boolean false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function fadvise
+ */
 static int os_fadvise(lua_State *L)
 {
     static const char *hints[] = {
@@ -652,6 +801,16 @@ static int os_fadvise(lua_State *L)
     return os_result(L, ec, NULL);
 }
 
+/**
+ * Commit any pending write to disk.
+ *
+ * @tparam File f a file opened for write
+ * @treturn[1] boolean true on success
+ * @treturn[2] boolean false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function commit
+ */
 static int os_commit(lua_State *L)
 {
     luaL_Stream *stream = luaL_checkudata(L, 1, LUA_FILEHANDLE);
@@ -660,6 +819,20 @@ static int os_commit(lua_State *L)
     return os_result(L, ec, NULL);
 }
 
+/**
+ * Place or remove a read (shared) or write (exclusive) lock to a file.
+ *
+ * @tparam File f a file opened with appropriate mode for the requested lock
+ * @string mode lock mode, any of 'r' (read), 'w' (write), 'u' (release lock)
+ * @int[opt=0] start initial offset for the requested section
+ * @int[optchain=0] len length of the requested section, 0 has a special meaning,
+ * indicating the whole file starting from the initial offset
+ * @treturn[1] boolean true on success
+ * @treturn[2] boolean false on failure
+ * @treturn[2] string error message
+ * @treturn[2] int system error code
+ * @function locking
+ */
 static int os_locking(lua_State *L)
 {
     static const char *modes[] = { "r", "w", "u", NULL };
@@ -674,6 +847,53 @@ static int os_locking(lua_State *L)
     return os_result(L, ec, NULL);
 }
 
+/**
+ * preferred path separator char: '\\' on Windows, '/' anywhere else
+ *
+ * @string sep
+ */
+
+/**
+ * Directory handle.
+ *
+ * Allows convenient file traversal on directories.
+ * Entries traversal order is system-specific, and may not be ordered at all.
+ * Provides metamethods: __gc to close directories on garbage collect,
+ * __close (on Lua 5.4) to close directories automatically, and __tostring for
+ * adequate formatting.
+ *
+ * @type Dir
+ */
+
+/**
+ * Read next directory entry.
+ *
+ * @treturn[1] string next filename in directory, '.' and '..' are also returned
+ * @error[2] error message on failure
+ * @treturn[2] int system error code
+ * @raise error message when attempting to read from a closed directory
+ * @function readdir
+ */
+
+/**
+ * Read and filter subsequent directory entries.
+ *
+ * @tparam[opt] function filter a function taking a filename string and returning
+ * a boolean to accept/reject each entry
+ * @treturn[1] {string,...} subsequent filtered contents, '.' and '..' are always filtered out.
+ * @error[2] error message on failure
+ * @treturn[2] int system error code
+ * @raise error message when attempting to read from a closed directory
+ * @function listfiles
+ */
+
+/**
+ * Close opened directory.
+ *
+ * @raise error message when closing a directory twice
+ * @function close
+ */
+
 static void createmeta(lua_State *L)
 {
     static const luaL_Reg metameth[] = {
@@ -703,9 +923,9 @@ static void createmeta(lua_State *L)
 DF_OSXMOD_API int luaopen_osx(lua_State *L)
 {
     static const luaL_Reg funcs[] = {
-        { "listfiles", os_listfiles },
         { "opendir", os_dir_open },
         { "dir", os_dir },
+        { "listfiles", os_listfiles },
         { "stat", os_stat },
         { "mkdir", os_mkdir },
         { "getcwd", os_getcwd },