Confluence Data Center
Atlassian announced Confluence Data Center as part of the Confluence 5.6 announce. All add-ons are tested on Confluence Data Center, usually on the most recent released version of Confluence.
For Confluence Questions related support, the most recent compatible version of the Questions add-on is tested and supported.
Compatibility for Atlassian Command Line Interface (CLI) generally follows the compatibility list above. More detailed compatibility can be found dependent on the ACLI release being used.
Confluence 4.3 introduced an incompatibility by changing templates (global and space) to use the new editor and storage format instead of the previous wiki markup. A number of macros listed here provided a capability to bring in source (normally plain text or wiki markup) from templates. The capability to do this is for more advanced users like Confluence administrators (for global templates) and space administrators (for space templates). If this capability is being used on your site, beware of upgrading to Confluence 4.3 or later. Recent versions of plugins will provide mitigations for this usage but templates will at least need to be minimally changed to revert to existing behavior . Alternatives like using attachments instead of templates will also resolve the problem.