With build 642 we’ve added an awesome new feature called Background Parse. It is designed to let you get right to work on your project as soon as Understand opens, instead of needing to wait for the parse. Right away you’ll have access to the Project Browser and Editor windows, and as soon as the parse is finished, everything else will be available.
Other features added since the release of Understand 3.0:
Added build system monitoring with buildspy
Added support for Windows 8
Improved project building capability
Improved Visio Export
Added ability to annotate code