For those out of the loop, Blender is the leading open-source graphics application for 3D modelling and similar work. Blender 2.58 is significant in that it's much more stable than earlier 2.5 stable/development releases thanks to hundreds of bug-fixes, is now more feature complete, and is the second to the last release of the Blender 2.5 series before the developers turn their focus to Blender 2.6.
The Blender 2.5 series features an updated user-interface, new Python add-ons, custom keyboard shortcuts, multi-monitor improvements, an improved tool system, and much more.
See the Blender 2.58 release log for more information and all of the details concerning this free software 3D program. The last Blender 2.5 series release, v2.59, is expected in August.