based on forum activity web2py was the second most popular python web framework (after Django) last time I checked. It is primarily unpopular among developers who haven't used it.
A really bad idea?
It is a really good idea for communities that don't have significant market share but still want an SO style forum. For example there is an OSQA backed forum for Esperanto speakers.
- well designed components: DAL, SQLFORM, views, etc
- commitment to backwards compatibility
- works on GAE
- helpful community (groups.google.com/group/web2py)
- thorough documentation (web2py.com/book)
The main criticism of web2py is that its design is not 'pythonic', which is irrelevant to me.