Alph Editor

Alpha Text Editor is a multi-modal, Tcl-programmable text editor for Mac OS X, optimized for TeX, LaTeX, and general source file development.

Alpha Text Editor (AlphaCocoa) is the modernized, complete rewrite of the classic Mac text editor, originally famous since the early '80s. Built on Apple's Cocoa framework for Mac OS X, this multi-modal, programmable editor offers exceptional capabilities for editing TeX, LaTeX documents, HTML web pages, and various source files. Its core strength is extensibility: most editing commands are written in Tcl, enabling users to easily customize behavior, create new bindings, and develop full-blown packages for specialized workflows.

https://sourceforge.net/projects/alphacocoa/