You need to go to: http://download.eclipse.org/eclipse/downloads/
and get the desired version.
i.e.: 4.5 Luna: http://download.eclipse.org/eclipse/downloads/drops4/R-4.5-201506032000/
There you can find several basic binaries, such us, SDK, Plug-ins, SDK-RPC, etc.
The smallest is: Platform Runtime Binary
More details in each binary: http://download.eclipse.org/eclipse/downloads/drops4/R-4.5-201506032000/details.html#PlatformRuntime
Anyway, if you want this basic version to install another plug-ins, such us, Dynamic Languages Toolkit then you need to download another version (it is not sufficent with only PLatform Runtime Binary).
