Computersight -

First of all, svn stands for subversion, and was created by CollabNet in 2000. You can use it to download things, and you can easily update the revision. For more in-depth information go to Wikipedia and search svn. For my  rsvn is used  to download addons for Gmod, knowing it is the latest version. Many popular addons are only downloadable by svn. Now I’ll give you a step by step guide on how to download stuff using svn.

1. The first thing you need to do is get a svn client. One popular client is tortiose svn. It is free and easy to use.
2. Now you need to find something to download with svn. They will give you the repository url and the username and password if there is any. If they don’t put a password and it needs a password try anon, or anonsvn.
3. Now make a folder on your desktop. Name it whatever, for example one of my favorite mods is the stargate mod, so let’s name the folder stargate and svn the stargate mod.
4. Now right click on  the folder on your desktop and click svn checkout. A window should pop up. In url of repository put whatever url you were given. For stargate this would be https://svn.wiremod.com/svn/stargate/trunk. In username and password again put what they told you, or if there’s no password just leave it blank. For stargate I would put anonsvn for both. If I needs a password then try anon for both or anonsvn.
5. Once it’s done downloading right click on the folder it downloaded to and go to tortoisesvn. Click export then export it into your addons folder.
6. This is very important. DON’T just copy paste everything into you addons folder, use the export. And DON’T just put the folder in your addons folder then not export. Both of these will leave tons of svn files that are not needed and will slow you’re Gmod loading time down a lot.