This is a rough version of the cmake.nanorc it works for my uses for the most part there are a few areas specifically with nested variables that it doesn't quite display everything as it should.
It highlights all the command keywords, comments, variables and anything in quotation marks.

Screenshots: 

In the rounds of looking for a specific syntax highlighting mechanism for Text Wrangler ( a fairly nice but large text editor for OSX). I found what I was looking for there but realized there was a problem with Text Wrangler, it would only start the syntax highlighter based soley on the extension of the file. This is a problem because I was looking for a syntax highlighting for cmake, and the primary build files are usually denoted as CMakeLists.txt files. I really didn't want to start the syntax highlighter for all txt files as I end up processing a large variety of files.