This is not a replacement for a CVS, but it is certainly useful in many cases. If you would like to revert your source code back to the way it looked an hours ago, the NB Eclipse IDE makes it easy. The key is to use Eclipses’ built-in local history manager.
This feature is already built-in to Eclipse IDE, but if you’d like to tweak it go to Window → Preferences → General → Workspace → Local History.
Click on the following picture to view a step-by-step video that shows how to use the NB Eclipse local history manager to replace the current source code file with any previously saved version.