Linux source control software needed

Our company are looking at switching from Windows to Linux for our software development environment.

I would be interested to hear any recommendations from users of this forum.

Thank you...


We need to find software to fulfil our source control needs. I've come up with a starting list of requirements based on what we've used in the past...and we have previously used both:

PVCS, http://www.merant.com/Products/ECM/VM/home.asp
Visual Source Safe, http://msdn.microsoft.com/ssafe/

Note: I have put an asterisk next to the requirements that I feel are a "Must" as opposed to "Nice to Have".

Check-in/out files *
The developer needs to be able to log into the source control app, find the file that they need (which is in a read-only state) and check it out to their development environment.

Version Labeling *
The developer should be able to see all versions of the file in question and be able to roll back to a previous version.

Audit Trail * (Who, What, When)
Who checked out the file last, and when. We should be able to enter text regarding what was done to the file as well.

Promoting files *
The ability to promote files from one environment (server) to another, i.e., from the DEV box to the UAT box.

View Code Changes *
We should be able to compare 2 versions of a file side by side, to see the changes that were made.

Archive Code

Organized Interface *
To enable us to see GUI of our enviroments, directories, etc.

Workflow
The ability to submit a code change through an approval process.

Browser-Based
Change Control
This refers to "bug tracking", i.e., "was it fixed", "which release"

Logical Changes
The ability to track changes to multiple files as one logical change.