In my search for a good HTML5 game engine, the only one I can find that has decent features, has good documentation, and isn't in alpha is RenderEngine. However, I barely ever hear about it. Is it just relatively unknown, or is there some glaring reason more people aren't using it? What has your experience been like?
RenderEngine like many other HTML5 game engines is still relatively new and unknown. That is why you haven't heard much about it. Just looking at it I can't really comment on how well it performs.
As it stands, the best place to find out information about it would be it's message board: http://groups.google.com/group/the-render-engine/topics or the Google Code Issues Page: http://code.google.com/p/renderengine/issues/list