After the trial period is done, it doesn't stop working, it just becomes nagware. All the functionality is there, but it will close itself after 30 minutes, and every once in a while will pause for five seconds to ask you to buy a license.

I've used the nagware version at work while waiting for purchasing approval. It's perfectly functional for the work I do, and only very slightly annoying. YMMV depending on your needs (I never need it for more than ten minutes at a time).