This is a 'no-change' release to workround the Xtext 2.9 API breakages.
The Neon 6.1 release preserves Luna/Mars/Neon installibility but imposes Mars Xtext 2.8.4 or earlier for developers wanting to extend OCL.
This Neon++ 6.2 release breaks Luna/Mars installability unless the Neon Xtext 2.10 is also installed. It allows developers to use the Neon Xtext.