In my software modeling class, we were using a relational language called Alloy. I am a big fan of Sublime Text 3 for all of my editing, so I wanted to use it for Alloy as well. After looking around, I couldn't find a syntax highlighting package for Alloy in Sublime, so I decided to make one. This was mostly to learn how syntax definitions work and to practice regular expressions. It now has most of the highlighting I was hoping for when I set out, but there is always room for improvement.
I used this guide to get a basic understanding of how to get started, even though it is for Sublime Text 2.
Any questions can be directed at firstname.lastname@example.org