GRIP is written using wxWidgets, a cross-platform GUI framework that wraps up native graphics API's. Most modern OS's come with wx installed by default, though in our experience it often takes some poking around or upgrading to work properly. It uses the DART engine for physics simulation. Grip can be used with Windows 7, Linux Ubuntu and Mac OS 10.7 or greater. Installation instructions can be found on Grip wiki.
For checking on current bugs or report a bug visit our Issues page.