Have you ever seen a successful technical community -- e.g. user group, industry organization?

Am I asking about a group of software engineers who get together F2F (or maybe online) and discuss technical and industry issues with deep zeal and interest -- a place where meaningful connections are made.

Here are the only examples I have ever seen:

• Open source
• Maybe the Silicon Valley Java Users' Group
• Homebrew Computing Club in the '70's

This sort of thing does exist in academia.

Of course, there are lots of conferences and attempts at user's groups. However, almost all committed, serious software engineers, when asked about this, say "I don't have the time", which means that the organizations are not worthwhile to the best in our profession.

Has anyone seen any organizations with an ongoing spirit of enthusiasm from top software engineers?