Subversion can be used from behind a proxy quiet easily.
Go to either (Windows)
sideways online download
watch nomad online and edit the servers file.
You need to have a entry like this in the file.
[global] http-proxy-host = someproxy.name.com http-proxy-port = 9999
Now you can connect out to external subversion servers.
You may need to read about (and set) the http-proxy-exceptions variable if you have internal and external servers.
There is also a
variable which may need to be set if your proxy requires authentication.