This software site repository URL,
http://download.eclipse.org/releases/luna/
provides access to the software repository for the Eclipse Luna release.

Until it is released in June 2014, it will contain milestone builds.

This repository site URL is typically pre-populated in the list of software repositories when you install the Eclipse Platform or SDK.

For more information about installing or updating software, see the Eclipse Platform Help.

There is also a collection of handy, downloadable all-in-one packages available for many interests and platforms. Many people find these all-in-one packages the easiest way to get started.