Earlier Today, the Eclipse Platform team announced  that from now on, the official builds of the Eclipse Platform will be exclusively produced using Tycho instead of PDE Build.
This is a major milestone in the life of the project considering that it has been using and evolving PDE build for over 10 years. This conversion from PDE Build to Tycho has been months in the making and required non trivial work from many people. Congrats to everybody involved!
Why this switch? To make it easier for a wider audience to build the Platform (see instructions), and more generally to align the Platform build with the rest of the Eclipse Ecosystem that is "standardizing" around Tycho (this is also being referred to as the common build infrastructure aka CBI).
Though the team feels confident that things are in a working state, it is highly suggested that you try out those builds to help us find any remaining issue that could have slipped in. To that end, just pick any I build from http://download.eclipse.org/eclipse/downloads/ and report your bugs.