concrete5.3 has been made possible by long hours, a great community of developers, and the kind license grants of these folks:
Aaron Swartz
This developer wrote the Python based engine we use to compare versions. It's the only script we've been able to find that actually does diff with an awareness of how HTML tags work. If you stop and think about it, you'll realize that's a HUGE challenge and this guy solved it with a few pages of code. You should hire him to think about very complicated problems if he's willing. He allowed us to bundle his GPL based script into concrete5 under the LGPL licesne.
http://www.aaronsw.com/2002/diff/
Jordan Michael
This designer does a lot of amazing work, is based in Chicago, and is gonna be someone you read about in magazines and books one day (if he isn't already!) We're using his file type icons in the new file manager because they're dead sexy, and work at a large scale. He's allowed us rights to redistribute them with concrete5 and we really dig that!
Thanks to both of these guys, it's awesome to be able to find something amazing on the web and use it. We'll keep doing our best to make sure the whole package is greater than the sum of it's parts!