Can we choose which plugins to load in eclipse on the startup?

Question

I am working on different technologies and frameworks. I write:

• web applications using GWT, Hibernate and Aptana studio.
  
• Android applications.
  
• Ruby on Rails web application with Aptana Studio.
  

Currently I am separating the projects in different work spaces, but my eclipse became for fat it consumes so much memory (it can reach +700mb). I thought about separate installations, but it doesn’t seem practical and it will eat up a lot of space.

I appreciate your answers.

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EDIT: Thank you for everyone. With both Maxym and zvikico answer from this question I can setup my workspaces more properly

Answer 1

Go to

Window > Preferences > General > Startup and Shutdown

here you will see "Plug-ins activated on startup", so you check/uncheck them

Answer 2

The UI contributions will not start a plugin. Only when you click a menu/tool bar item or open a view or editor or perspective, the respective plugin will be started. So just because of having those plugins in your installation won't eat up your memory. They won't be started until you actually use them.