Installing e4 July 2010
The most recent e4 release is the e4 July 2010 release.
Get a zip
e4 provides an "all in one" download, called the e4 SDK. This is a product that contains everything you would ever need to develop e4: the latest Eclipse SDK, EMF SDK, and all of the e4 bundles and source code, and parts of the Equinox SDK. Simply download the zip, unzip it, and run the eclipse.exe as you would for the basic Eclipse platform. This will launch an e4 SDK that you can use to try out the demos and experiment with an e4 application.
Secondary method: install manually
Use the e4 SDK if you can, but you can also install pieces of e4 individually (it's just a lot more hunting around).
Prep: Go to the integration builds page, navigate to the desired build (if you're not sure which to choose, use the stable build, then look down in the bottom right corner for "online p2 repo link". Copy the underlying URL.
- Select Help > Install New Software...
- Click on the "Add Site..." button and paste the URL.
- Select the features you want to install. They are organized by category.
- e4 Resources: Experimental work to support a resource model based on REST resource APIs
- e4 Runtime: Runtime components required by other e4 features
- e4 Server: Experimental Bespin server based on e4
- e4 TM:Toolkit Model. A declarative UI runtime based on EMF
- e4 UI: This will install the e4 UI runtime components. To be able to run the e4 photo demo (a RCP style application), you should check everything under the "E4 UI" category: Eclipse e4 CSS, Eclipse e4 UI, Eclipse e4 CSS Source, and Eclipse e4 UI Source. 
- e4 XWT: This will install the declarative UI runtime and its development environment. The "E4 XWT" feature contains XWT runtime and "E4 XWT Tools" corresponds to the development environment.
- Review the items to be installed and click Next.
- Accept (or not!) the license terms and click Finish.
Information on installing builds from the 0.9 (July 2009) release.
Installing 0.9 M4 or later
As of 0.9 M4, e4 provides an "all in one" download. This is a product that contains everything you would ever need to develop e4: the latest Eclipse SDK, EMF SDK, and all of the e4 bundles and source code. Simply download the zip, unzip it, and run the eclipse.exe as you would for the basic Eclipse platform. The 0.9 release build is available here.
You are now ready to try out the demos:
- SWT: Running the cross-compile-SWT-to-Flash demos (0.9 only)
- UI: Running the e4 photo demo, contacts demo, and the CSS examples
- XWT: Running the declarative UI demos
 Note that the Eclipse e4 UI work also requires the EMF runtime. This will be brought in automatically. However, if you wish to view or edit the UI model and you're not a fan of XML source editing, you will want to install the EMF SDK which provides the EMF .xmi editor. Follow "Help" -> "Install New Software..." -> "Models and Model Development" -> "EMF SDK - Eclipse Modeling Framework SDK 2.4.1 or 2.5.0", then restart Eclipse.