0.8.3 is a release on the 0.8 line, which brought in support for external service to Tez (TEZ-2003).
The APIs for external services continue to be unstable in this release, and can change in future version.
This release also contains the first iteration of the revised tez-ui (tez-ui2) (TEZ-2980).
All fixes from previous releases - 0.5.4, 0.6.1, 0.7.0, 0.8.2 are part of this release.

Major changes
1) Support for co-ordinating and running DAGs for external services.
2) Addition of tez-ui2

Please see CHANGES.txt for more details.