Souceforge had an enterprise edition (Disclaimer: I was a Sysadmin/support guy/developer of SFEE in my 7 years of working with that product). Unfortunately, SF.net's issue system is nothing compared to what JIRA or Redmine can do right now. While they have the File Release System or downloads, in theory, most places want that handled by a CI system -- something that Jenkins can do rather well with just about any type of file system or backend. User management? Most enterprises have some type of SSO or user management in place already, and the sf.net code didn't have the ability to use another source for user management.
The only thing that SFEE did well was provide a single 'neck' for customers to strangle when things went wrong -- and we became very, very good at keeping those customers happy.
If you're looking for the last public release of the sf.net code, it's from around 2003/2004, and it's....messy. SFEE (the product that I worked on) was acquired by CollabNet in 2006, and is now something called CollabNet TeamForge, but, I wouldn't use it for an enterprise anything these days).