Both GHC and Hugs use CVS (Concurrent Version System) to keep track of the sources. CVS lets several people work on the same software at the same time, allowing changes to be checked in incrementally.
You can browse the Haskell repository and inspect the revision history of each file.
Read-only access is available to anyone; there's no need to ask us first. The process for getting read-only access to our repository is pretty straightforward:
Set your CVSROOT environment variable to :pserver:anoncvs@cvs.haskell.org:/cvs
The first time you access the repository, you'll need to do cvs login. The password is simply cvs. This sets up a file in your home directory called .cvspass, which squirrels away the dummy password, so you only need to do this step one time.
If you see an error message that begins PAM start error, then you haven't entered the password correctly.
Now, you can check out a source tree using normal CVS commands. Getting a brand spankin' new set of Hugs98 sources is a simple checkout away:
$ cvs checkout hugs98
The Haskell CVS Admins
Last update: 28 September 2005