Blender is a free open-source 3d modeling program available from blender.org.

There’s no shortage of tutorials regarding modeling, texturing, animation and other subjects for blender, but basic info on the user interface is tough to come by. Surprising, considering that 90 percent of understanding blender comes from wrapping your head around the interface. Once you get past that, it’s a whole new world and a what was once a dense program suddenly makes a lot of sense.  Some fine tutorials can be found by searching youtube; some more cool tutorials can be found at gryllus.net

The cool thing about the UI is I started to wonder about it being applied to other programs like a word processor. What if you could just slide open a new window in Word, and then make that window another view port in a long document for easy cut and pasting, then make that window into some type of sub-menu system, drawing area, wysiwyg output. or html preview, withouth having to hunt for them in menus. Really cool stuff.