This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
Aha, so you're not looking for an online version control system.
You can just download Subversion and set up your own server with it. If you're using Eclipse, then you can install the Subclipse plug-in so that you can check in and out from inside the IDE. NetBeans already has built-in Subversion support as far as I know (you don't need any special plug-in).