http://www.freshmeat.net is a clearinghouse for information about open source (although not limited to open source) projects. The front page contains announcements of new releases. You can also search the Freshmeat database or browse it by various categories, including programming language. You can also subscribe to particular projects, in which case you will receive email whenever a new release of the subscribed project is announced.
Subscribe to the Freshmeat newsletter to receive automated daily digests of the days announcements: http://www.freshmeat.net/newsletter/
Swik is another site for open source listings.
LV Note that freshmeat, as far as I am aware, isn't a site where one would store open source code, but instead, one registers where their project can be found, info about the current release name, categories about the software, etc.
See SourceForge as one of the sites where one can actually run a project, storing code, publishing docs, etc.