Our compositor is really small (both code and feature wise) and intently focuses on filling the niche of a high-performance OpenGL compositor for handhelds or slightly larger devices. It's not really something you would want to use even on your laptop at this time. It does some quite innovative things like seamlessly un-redirecting the rendering for windows that fill the device screen, which is perfect for a handheld but doesn't make sense in other type of setups.

That said, the Harmattan UI framework can, and has been, run with other window managers and compositors. The apps don't really make any assumptions in this regard. Still, while the apps can technically be run in software by switching the graphics system, we see it as critical to the user experience that we can depend on OpenGL acceleration being available to us. So we are setting the minimum hardware baseline at the N900 level for the entire framework, and not making any compromises in order to also scale downwards.