Valid license holders for Optimizer Pro will continue to receive support if required, but the product has now been removed from sale, in preparation for the release.
I want to say a big thank you to everyone who's enjoyed using the plugin to optimize their sites over the last six and a half years, and wish you all the best for the future.
This section details Optimizer Pro's current compatibility and software requirements.
NextGEN Gallery Optimizer v1.0 to v1.1.2 was written for the original (now Legacy) NextGEN codebase v1.6.2 to v1.9.13.
As of Optimizer v2.0, the plugin is also now fully compatible with the new NextGEN v2 codebase (v2.0.0 to v2.1.60), the original NextGEN Legacy codebase (v1.6.2 to v1.9.13), as well as the NextGEN Legacy fork called NextCellent Gallery (v1.9.14 to v1.9.31).
NextGEN Gallery Optimizer is compatible with all versions of WordPress from v3.7 to the latest v4.7.
As of version 2.0, Optimizer now requires PHP 5. This is the same as WordPress itself since v3.2, which was released in July 2011.
This shouldn't cause any issues as according to the stats, it appears no current WordPress installs are using anything less than PHP 5.1.
Not at the moment, however we are looking to add support for multisite installs in a future release of the plugin.