org.eclipse.php.help plugin of rc1 requires org.junit4 plugin. You can get
it from Eclipse Classic package or Eclipse IDE for Java Developers package
or... Also you can edit Manifest.mf in org.eclipse.php.help plugin. Remove
'org.junit4' from 'Require-Bundle'. (If you cannot wait 1.0.3 release)
I believe this unnecessary dependency will be removed from 1.0.3 release...