Subversion (SVN) support can be added to Eclipse Helios by following these steps:
- Add a new repository: http://subclipse.tigris.org/update_1.6.x . 
- Install SVNKit Library, JNA Library, Subclipse, Subversion Client Adapter, Subversion JavaHL Native Library Adapter, and SVNKit Client Adapter. 
- Add these 2 lines immediately after -vmargs in eclipse.ini: 
-vmargs
-Djava.library.path=/usr/share/java/
-Djava.library.path=/usr/lib/jni/