Is eclipse installation portable?

Yes. Eclipse is portable. However you need to specify the workspace folder and the Java VM on the command line. This prevents eclipse from using the broken VM that comes with windows and allows it to access the workspace even if the drive letter has changed.

eclipse.exe -clean -vm %JAVA_HOME%/bin/javaw.exe -data %WORKSPACE%

FYI: The Java VM is also portable so you can put both Java and Eclipse on the same thumb drive.

NOTE: Eclipse project settings may not be portable. This depends on how you set up your .classpath file. Try to use relative paths whenever possible.

Eclipse does store all of its plugins and configuration in its own directory structure, so making it portable it surprisingly easy and intuitive. I've used Eclipse in a portable fashion with no problems at all. All I can recommend is a couple of extra steps to make your life just that bit easier and this is what I do:

I just download the Eclipse zip file, extracted it to a directory on the desktop and do the following steps.

Copy the Java runtime from a computer that has it installed into your Eclipse directory. The folder with java in it should be named "jre" so you end up with the following:

Eclipse
|
|___jre
    |___bin
    |   |___files
    |
    |___lib
        |___files

This means it can work on any machine that doesn't have Java installed without having to run special command line or path settings. Just run eclipse.exe and it finds the Java runtime in jre for you and carries on happily. Neato.

After that when Eclipse asks for a workspace I simply enter .\Workspace so that the workspace directory is created within the eclipse directory, and it seems that all the workspace details are kept under that directory in a "relative directory" fashion so it doesn't matter if the drive letter changes. Plugins like Pydev keep their settings in the workspace folder (in a folder named ".metadata") so once you've set it up they'll get remembered between places too.

And Voila, portable Eclipse.

You can copy this Eclipse directory between places and it all seems to "just work".

Did you try Eclipse Portable? Some of my friends use it and they say it works well.