As of 2013-21-11, at least drupal 7.24 is required
The authcache 2.x branch is everything about breaking up the code into several submodules. First this allows deactivating support-code for core-modules not in use. Second by using our own API, it will automatically improve such that third-party integration becomes much easier.
The following things changed in the 7.x-2.x branch:
Last updated: April 28, 2015 - 12:43
Last packaged version: 7.x-2.0-beta4+14-dev
Nightly development snapshot from branch: