Subversion is an excellent version control system. It is mature enough to have all sorts of integration - with Apache and Python amongst others. This enables easy communication via the HTTP protocol and language bindings, such as python to form web interfaces for repositories.
With subversion being a server-client model the version of the server is the most important component as it determines what features you can actually use. No good having a 1.6 client if the server is 1.2 as only 1.2 features are available. Depressingly this was the situation I was in. Unsurprisingly, the good folk at CollabNet have added lots of useful new features, which I need to use.
Compiling subversion is actually dead easy (as I have discussed previously, plus lots of binaries are available). So what is Subversion Edge? Essentially a bundle of Apache, Subversion and ViewVC server in a convenient tarball. Then throw in a bonus admin web interface as well. Upgrading your server version becomes slightly more tricky when Apache and Python are tied to it. No worries with Subversion Edge as it has a built-in update mechanism. One of my pet peeves is multiple usernames/passwords. Another freebie from Subversion Edge is LDAP support so plug straight in your authentication system - nice. One less component to ensure you compile against.
I started using the beta over the summer and have had no problems. The 1.2.1 release is now happily serving many repositories for me. If you run a very large and complicated setup you may find Subversion Edge is too restricted for you, but for a large number of users it will meet your needs.
If you maintain subversion repositories I strongly recommend you give Subversion Edge a go today. Did I mention it was free as well?