I spent this afternoon trying to get the Eclipse PDT plugin to install and work in "Eclipse 3.4 (Ganymede)":http://www.eclipse.org/ganymede . I have never been able to get the PDT plugin to work on the first try since the PDT project was started. There has always been some fumbling and bumbling on my part trying to follow their "terrible directions":https://bugs.eclipse.org/bugs/show_bug.cgi?id=204337 and having no luck. This is, of course, followed by some magical event that suddenly makes PDT work great until I run in to a silly bug. The current bug that has bitten me is the stuttering of the editor for a few seconds while typing. Try being a touch typist and having your groove stopped short by a slow editor. It is not fun -- although it does bring back memories of a 1200 BPS modem I had in the 90's . Today I tried to update to the latest integration build of PDT: "I20080909":http://download.eclipse.org/tools/pdt/downloads/release.php?release=I20080909 . Guess what? No luck and it is non-functional. Here is the Java stack trace when I open a PHP file: pre. java.lang.NoClassDefFoundError: org/eclipse/php/internal/core/preferences/IPreferencesPropagatorListener at java.lang.Class.getDeclaredConstructors0(Native Method) at java.lang.Class.privateGetDeclaredConstructors(Unknown Source) at java.lang.Class.getConstructor0(Unknown Source) at java.lang.Class.newInstance0(Unknown Source) at java.lang.Class.newInstance(Unknown Source) Here is "bug #239210":https://bugs.eclipse.org/bugs/show_bug.cgi?id=239210 which looks like my problem and links to my exact problem ("Bug #239723":https://bugs.eclipse.org/bugs/show_bug.cgi?id=239723 ). I wish the PDT project would get its act together and be a better open source project. Release early, release often does not mean just dump out stuff that is in some strange intermediate state. It means release it so that someone in a real world situation can reasonably consume your software.