You'll need at least JDK 8 installed in your system. Make sure your e(fx)clipse installation uses this JDK when you launch your Eclipse instance!
For the lazy ones who prefer an all-in-one download, we provide preconfigured packages so that you don't have to worry about all the different bits and pieces.
For those who'd like to assemble their own e(fx)clipse installation based on Eclipse 4.5.x we offer an installation guide which helps you get started.
To install the e(fx)clipse tooling into your already existing Eclipse you have to add an Update site. There's no released yet available so you need to add the release update-site http://download.eclipse.org/efxclipse/updates-released/2.3.0/site and http://download.eclipse.org/modeling/tmf/xtext/updates/composite/releases/ for the needed xtext dependencies.
Download the latest release of the Eclipse 4.5 SDK.
Fire up your Eclipse IDE if you have not done so already.
e(fx)clipse is an extension for your Eclipse IDE which is delivered as a so called p2 repository. Extensions like this can be installed using the "Install New Software" wizard.
Eclipse does not know about the location of the e(fx)clipse p2 repository so you need to add the repository as a software site. The address is: http://download.eclipse.org/efxclipse/updates-released/2.3.0/site
In the tree of installable features, check only the entry corresponding to your release:
Also, make sure the "Contact all update sites during install to find required software" is checked.You may, however, install the FX Runtime feature into your IDE but we strongly recommend composing your own target platform.
Go through the wizard and let p2 do its job.
When requested, restart Eclipse.