I wrote about AJAX automation vendor ClearNova recently, but too soon to get in on their more recent decision to go GPL open source with the runtime element of their offerings. Heck, the stuff was already 60% open source.
ClearNova, like a lot of start-up software vendors, has bitten the bullet and recognized that the licensed proprietary software business model is too akin to paddling upstream using a pencil against a category 4 whitewater. Better to go open source and allow the winds of viral adoption to fill your sails and deliver you in the direction your users deem best.
The Workbench element of ClearNova RAD suite remains $500 per year per developer. And ClearNova is offering a strong services business alongside the product, which becomes in effect, their real growth business. It worked for JBoss.
Given the hot attention from traditional IDEs to AJAX, to provide AJAX tools functionality as an adjunct (soon integrated component?) to their exisitng tools, ClearNova should benefit from both a partnership-driven demand as well as the steep adoption curve from open source frameworks communities.