Patent Policy
The WHATWG now has a patent policy, the WHATCG. We will keep using the same mailing list, the same IRC channel, the same web sites, but now sometimes we will publish through the WHATCG as well for patent policy purposes per the W3C Community Final Specification Agreement.
If you could previously not join the WHATWG because no patent policy was in place, now is the time to reconsider. If you are unsure how this applies to you, then it most likely does not.