Speaking of open-source animation software, the Blender Foundation has just released Blender 2.77. This is a relatively minor update, maintaining compatibility and structure with other 2.7x versions, but it has some interesting aspects to it. While there will probably be other 2.7-level updates before then, 2.8 is internally described as “the Workflow release,” which is also starting to be discussed by the foundation.
The headline feature is improved Cycles ray traced rendering, especially on GPUs. Both quality and performance get a bump, and a few particle effects are now GPU-aware. Personally, I am very interested to see how the “Edit-mode boolean tool” will work. I started 3D modeling with a NURBS-based CAD tool, and booleans were pretty much your first choice to get anything done. I then transitioned to Maya, which had the worst boolean tools I've ever seen, choosing to delete both objects if it couldn't figure out how they combine (and that was basically anything other than two plain primitives). It was liberating going to Blender, where I had a boolean tool that mostly worked, but it still causes a few glitches here and there. I'm hoping that, now that it's a default tool, it will continue to grow in robustness.
This is also the first release that (officially) ends Windows XP support. I mean, it's open source. Compile it for whatever platform you like. But you will not be able to upgrade to 2.77 with the official builds, and there's no telling how complicated back-porting will become going forward.