Version : 4.0.x (2016-04-30)
Better text tools and vector art capability, python scripting support, etc.
Version : 3.0.x (2015-04-30)
Better performance, animation support, layer, workflow, transform, filter, brush, etc.
Version : 2.9.x (2014-06-30)
Faster Development, better PSD support, layers, masks, brush, resource manager, display, etc.