As I switched with my projects recently from Sourceforge, I had a look at some project-hosting-platforms. This list is sorted alphabetically.
Berlios
http://www.berlios.de/
Berlios has taken the old Open-Source-Software from Sourceforge and developed it some further. Now it looks uglier than Sourceforge itself. ;-) It has most of the older features of Sourceforge (That does not include hosted apps). Berlios hosts more than 5000 projects.
- free for: open-source software
- supported version-control-systems: CVS, Subversion, Git, Mercurial
- Communication: Forum, Mailinglist, Wiki
GNA!
https://gna.org/
GNA! is a hosting-platform of the GNU-project, but also non-gnu-projects are allowed, if they conform to free licenses and can run on a completely free system (for example: Windows-only-program are not allowed, but multiplatform Linux/Windows-programs). Interesting is, that GNA also allows Documentation- and Organization-projects. GNA supports releases, projectsites, issue-tracking, news. Nice feature is, it hosts the GPG-key of project-members. Clean UI, seems a good choice. I would have tested it, but I never got the e-mail for validation of my account, so I wasn't able to use. Hopefully a temporary problem. GNA hosts more than 1000 projects.
- free for: open-source software, free documentation and organizational projects around free software
- supported version-control-systems: CVS, Gnu Arch, Subversion
- Communication: Mailinglist
Google-Code
http://code.google.com/hosting/
The hosting-platform from Google. It has the nicest and cleanest interface of all contestants. It has a Wiki, Downloads, an issue-tracker and supports subversion and Mercurial. Projects get tags and you can search for the tags. Google restricts the licenses you can choose, but as the accepted licenses are very common Open-Source-Licenses, that seems no big problem. The problem for me was that you need a google-account. So Google can gather much data from the different services they have and can combine all the data for you as a user. Even worse: Every user who wants to submit a bug has to sign on for an Google-account. Google might be not evil, but I don't want to give them the chance to become evil. Besides that the platform looks very good.
- free for: open-source software
- supported version-control-systems: CVS, Subversion, Git, Mercurial
- Communication: Wiki
java.net
http://java.net/
java.net is a project-hosting-site for only Java-projects and Java-related communities. It has the same overcomplicated issue-tracker, that tigris also have. Other than that, the typical support, releases, website etc.
Note: Kenai and java.net will be merged in the near future.
- free for: open-source software in Java or Java-related
- supported version-control-systems: ?
- Communication: ?
Kenai
http://kenai.com/
Kenai from Sun is a new contender and Beta at the moment. It has Forums, Mailinglists, Wiki, an issue-tracker, allows sub-projects, and supports hosting of Subversion or Mercurial. The UI of Kenai looks good, projects can be tagged and it has a tag-cloud.
Note: Kenai and java.net will be merged in the near future.
- free for: open-source software
- supported version-control-systems: Subversion, Mercurial, Git
- Communication: Forums, Mailing-lists, Wiki
Microsoft Codeplex
http://www.codeplex.com/
Codeplex has a nice, but not very simple interface. It features releases, website, issue-tracker, statistics and Subversion/Team Foundation Server or Mercurial for source-code-control. The issue-tracker allows to vote on issues, very nice. Projects can be tagged and CodePlex shows a tag-cloud. CodePlex supports continuous-integration with CruiseControl.net - great feature.
- free for: active open-source software
- supported version-control-systems: Subversion/Team Foundation Server, Mercurial
- Communication: Forums?
Origo
http://www.origo.ethz.ch/
Origo is created by the ETHZ, a well-known university in Switzerland. Origo has a clean UI, supports Wiki-sites, Forums, a blog and releases (no mailinglists). The issue-tracker is simple in the usage. The supported version-control is Subversion. Origo support software-and non-software-projects and also Closed-Source-Projects. Origo has some basic social-networking abilities like friends.
- free for: software and non-software
- supported version-control-systems: Subversion
- Communication: Forum, Blog, Wiki
Sourceforge
https://sourceforge.net/
Sourceforge is the classic and the most projects will use it. It has many features, as an Issue-Tracker, Mailinglists, a Wiki, Forums, support for many version-control-systems, a shell-server, statistics, file-releases and much more. It hosts thousand of projects and is well-known. Sourceforge seems to be the only platform that allows to submit issues anonymously. Since 2001 the software behind Sourceforge became Closed-Source, before it was open-source. The subversion-server is somewhat slow. The UI looks nice, but in my opinion the main project-site gets fast too crowded. Too much information at once is a little bit confusing. The UI can be used without Javascript for normal users, but project-admins will need Javascript for some functionality, especially for file releases. Sourceforge allows to access all sites via https. Sourceforge has advertisements on the sf-sites (the site it hosts for you is fully under your control and contains no ads, except you put them there). The killer-feature are without a question the hosted apps. If you dislike the (mediocre) issue-tracker from sourceforge - deactivate it and use Trac or Mantis. You can also deactivate the forums and use phpBB. Wordpress, Mediawiki or different project-management-tools are other options. Hosted apps are a great addition.
- free for: open-source software
- supported version-control-systems: Subversion, Git, Mercurial, Bazaar, CVS
- Communication: Forum, Mailinglist, as hosted app: Blog, Wiki
Tigris
http://www.tigris.org/
Tigris has a nice website, supports Subversion and has also releases and mailinglists. The issue-tracker is overcomplicated in my opinion. Tigris is restricted to only projects, that create tools for software-developers.
- free for: open-source tools for software-developers
- supported version-control-systems: Subversion
- Communication: Forums, Mailing-lists, Wiki
Good, I hope this list gives some key-features of some typical sites. I hope I forgot no important site. I myself transferred my projects to origo, but decide for yourself. I will try to update this answer, as I get new information.