I'm having difficulty getting PyDev to work.
I had an installation of Eclipse for PHP developers (1.2.1.20090918-0703). A month ago, I installed PyDev, and everything worked great. I go to fire it up this morning, and PyDev is gone. There is no option to create a Python project, the Python language editor is missing, etc. 
Eclipse for PHP does not say that PyDev is installed, so I grab it from the update URL. The version that comes down is 1.5.6. I restart after the installation, and everything works fine again. Sweet.
Then, I grab Subclipse 1.0.7. Upon restarting after that installation, PyDev is now gone. It isn't recognizing Python projects or Python files, etc. So I uninstall Subclipse. PyDev is still gone. Uninstalling and reinstalling PyDev again doesn't bring it back.
What am I doing wrong? Do I need a different version of Eclipse?
UPDATE: I downloaded a fresh copy of Eclipse for Java, did all this over again, and had PyDev working fine. Then, when I downloaded JSEclipse, PyDev again disappeared. This is super frustrating.
UPDATE 2: Another fresh copy of Eclipse. This time I downloaded Subclipse first. It worked fine. Then I downloaded JSEclipse, and Subclipse is gone.
there's an easy way to install plugin for eclipse, download the pydev package zip file (not install it via eclipse update), extract it, and put it into your eclipse/dropins/pydev folder.
this is a hidden way to install plugin.
Eclipse: PyDev installation difficulties