OroborOSX is an X11 environment designed for use in rootless mode with XDarwin on Mac OS X. The source code is also available.
X11 windows are interleaved with Aqua windows (the usual rootless
XDarwin implementation brings all X11 windows
in front when one is clicked);
Clicking in a background window will only activate that window
(rather than the click being sent
through to make something else happen in that window);
A list of X11 windows is available from the OS X Dock icon (and the
Window menu in OSX10.1);
New 'X11 application' icons can easily be created from the template script;
X11 applications can be launched from the "Launch" menu;
X11 applications can be launched by double-clicking on them;
Completely self-contained package -it is much more 'Mac-like' in that it
does not interfere in any way with any 'unixy stuff', so you
can use it safely with any software downloaded by fink, for example.
What's new in OroborOSX
Version 0.9 adds a much-improved internal version of XDarwin (with hardware 3D OpenGL, faster drawing, faster resizing, etc.); new 'presentation mode' (hides Menubar and Dock); new command-key-shortcut mode (no longer need to have the cursor in the menubar to use keyboard shortcuts); on-the-fly X11 keyboard switching; rules to set the default properties for classes of X11 windows; works with an installation of Apple's X11; works with OSX10.3 (multiple users and Expose); numerous other tweaks and fixes (see the version history for more details).