Linaro is a consortium entity of developers helping to advance the state of open source software on ARM. The BeagleBoard is one of the supported reference platforms.
From the Linaro FAQ : Linaro provides daily patches to upstream projects, monthly source code releases to make the latest code and tools easily available and Linaro Evaluation Builds for popular Linux based distributions such as Android and Ubuntu. The platform team continuously build and test the latest open source code on our members hardware to ensure product quality software. Current Working Groups include: Graphics, Multimedia, Power Management, Kernel consolidation and tools.