Rated 4 out of 5 stars

This is a great addition to Firefox that will soon become indispensable to me, I believe. There are a couple of features I'd love to see added, though:

1. Space bar triggered expansion. At the very least, some key/key combo that's less cumbersome than Ctrl+Alt+Whatever
2. User specified cursor placement. I'd like to be able to insert opening and closing delimiters with the cursor waiting for me to type in between.

Otherwise, great add-on. Particularly handy since I work on both OS X and Linux and my shortcuts work across both systems. I wasn't looking forward to becoming dependent on something (e.g. Text Expander) that had no analogy in Linux. This might just solve that problem.