CC Mode is a GNU Emacs and XEmacs mode for editing C and other languages with similar syntax; currently C++, Objective-C, Java, CORBAs IDL, Pike, and AWK. It is a standard package in both GNU Emacs and XEmacs.
A Cocoa port of GNU Emacs for GNUstep and MacOS X.
A Cocoa port of Emacs for MacOS X and GNUstep
Alpaca is a programmable rich-text editor for authors using Mac OS X. It is built on, and programmable in, Common Lisp, and has a complete Common Lisp programming environment built into it.