OSX programs crashing, 'Kernel: file: table is full'
I solved my own problem - but figured I'd answer for anyone else searching for the same thing. 

I run CodeKit to help minimise CSS and JavaScript when building websites. The program works beautifully, but I had it monitoring all the sites (25 or so) I'd built over the past year or so for changes when it was open. I figure this was causing it to open (or at least monitor) thousands of files, resulting in the file table issue.

By only selecting the site I'm working on to monitor, everything is working perfectly (again) and as a plus - the CodeKit CPU usage has dropped dramatically.