Part of the strategy was to address a growing need to have an open source accessibility tools framework. One reasoning was that propriety test tools on Windows prevented us from distributing a modified version of the Windows accessibility test tools of IAccessible2 to developers. Another reason was that creating test tools from scratch was a time consuming process. Why not take the ones we were creating, internally, and donate them to the industry to build upon, free of encumbrances. Also, due to the overwhelming success of Eclipse, we felt it was an excellent place to build a community around a reusable and extensible tools framework that provide developers, consultants, and new technology providers with a starting point. The result is ACTF.
In ACTF we will be donating new tools like "AccProbe" which will allow you to do IAccessible2, MSAA, and WAI-ARIA testing. We will have new browsers and validation tools as well. The best thing about it is that you can participate, or borrow what is there as you see fit ... and you don't have to sign a license agreement!