Since the Eclipse N4JS project is in incubation phase, we do not provide release versions yet. Below download links refer to a recent nightly build and are updated on a regular basis. You can browse all latest builds here.
Please further note that at this time only the macOS build of the N4JS IDE is thoroughly tested. Builds for other operating systems are experimental and installation of the individual plugins into a running Eclipse via the update site is not recommended, at this time (though using the update site for updating a previously installed N4JS IDE should work fine).