Eclipse's Subversive plug-ins allow usage of the Subversion version control from within your Eclipse workspace, however these plug-ins require a SVN connector in order to work.
This connector is based on the SVKit toolkit, which in itslef is a pure Java based SVN library.
Apart from offering Subversion functionality this connector also allows you to extend and plugin your own custom conflict resolution handler, using Eclipse's extension points.
For more information see the Wiki.