If you’re running Mac OS X and want it to be more like OS 9, you may be interested in the new X-Assist, a freeware utility from shareware author Peter Li.
The app brings OS 9 features to Mac OS X. It adds a windowing mechanism where all windows are switched back when a window is clicked on, instead of just the window being clicked on, like in OS X. It adds a familiar Application Switcher Menu to the top right corner of the screen. It offers the ability to add personal hierarchies of items in an OS 9-like Apple menu. X-Assist users can add any hierarchy into a “Shortcuts” submenu. There’s even an extensible “Control Strip” like plug-in architecture.
X-Assist supports Objective-C (NSBundle) plug-ins. Li says they’re easy to write. Two examples, “SetVolume” and “MP3 Player,” plug-ins are provided.
You can download X-Assist 0.1 (a 506 k file) from Li’s Web site.