The WHATWG specs contain a lot of innovation, but change more rapidly. In many cases WHATWG specs are living documents that gradually evolve and adapt to chang

The WHATWG specs contain a lot of innovation, but change more rapidly. In many cases WHATWG specs are living documents that gradually evolve and adapt to changes in real time. Conversely the W3C specifications are fixed to versions and are occasionally patched with updates. The W3C process is incredibly slow and conservative, which frustrates developers on the bleeding edge. Due to the slow process, thoroughness of that process, and formal versioning most software vendors prefer to implement against the W3C publications as more stable or reliable.