Is there any venue to meet people interested in doing open source projects of semantic web? (A kind of sourceforge, but especialized).
There is also SemWebCentral at http://www.semwebcentral.org/, which hosts a number of Semantic Web tools. From the web site:
SemWebCentral is an Open Source development web site for the Semantic Web. It was established in January, 2004 to support the Semantic Web community by providing a free, centralized place for Open Source developers to manage Semantic Web software and content development.
I know I've seen quite a few groups on Meetup, just search "semantic web".