Sublime LC3 is a syntax highlighting package for LC3 16-bit assembly for Sublime Text 2.
Install:
cd .config/sublime-text-2/Packages
git clone git://github.com/wufufufu/Sublime-LC3.git
Download and install AAAPackageDev.
In the folder Sublime-LC3 is the file lc3-assembly.JSON-tmLanguage which contains the editable JSON version of the grammar. Use AAAPackageDev to regenerate lc3-assembly.tmLanguage from this file.