OpenWrt is a slimmed down Linux distribution designed to run on alls sorts of hardware. It is especially suited for embedded hardware like home routers, pocket computers or smartphones. OpenWrt holds the record for fastest time-to-boot-plus-WM on the XO, just under 20 seconds (without networking up yet).
A few XO related projects are underway. The OpenWrt folks are actively working on other hardware that generates mesh networks, and interested in improving the XO mesh implementation.