SketchUp 2013 is released! This is an entirely new version now based on the year rather than the version sequence. There are some notable changes such as: the free version has been named SketchUp Make; toolbars are rebuilt and stay in place; and LayOut (a program sold with the Pro version) has performance increases. The newest feature is the Extension Warehouse for SketchUp ruby plugins. This lets you search, download and install plugins from inside of SketchUp! For more on all that’s new go to their SketchUp Pro New in 2013 page or more details including known issues can be found on their Release Notes page.
Extension Warehouse