The goal of CodeEditor is to be a good non-rich text code editor.
CodeEditorView offers a subclass of NSTextView and supports syntax
highlight, mark delimiters, etc. It can be used in other projects.
Features

    * Faster than ever
    * Tab View: Don't need to open so many terminals again.
    * Toolbar: Use "Alt (left) - t" to open/close a simple toolbar on the fly.
    * Find (Regular Express support) and replace.
    * File Inspector.
    * Change font attributes and preference instantly without restart.
    * Periodically or manually Highlight keyword with difference attributes
      according to the language.
    * Automatically or manually find delimiter pair.
    * Automatically indentation according to the preference.
    * Support scripting (need StepTalk). 

WWW: http://savannah.nongnu.org/projects/codeeditor/