Our o11s project has created the first implementation of the IEEE 802.11s draft. This mesh stack has been integrated in the Linux kernel wireless subsystem in the 2.6.26 release, amounting to one fifth of the code of the complete Linux 802.11 stack (mac80211).
This implementation is hardware independent and can easily work with any softmac wireless chipset. Many chipsets such as those from Atheros, Broadcom, and Zydas are already supported.