This is VK/KittenPHP-DB-Engine project, consisting of efficient PHP-to-C++ translator called "KPHP" or "KittenPHP", and several auxiliary high-performance "engines" (specialized non-relational databases), needed for its deployment.
It has been developed since 2009 mostly by Vkontakte Ltd, operator of social network VK.COM, and thoroughfully tested in high-performance enviroments, until a version useful for the general public was obtained. Fulfilling several previously given public promises, this version is now released for public use under GPL/LGPL terms.
Source code is licensed mostly under GPL version 2 or later (see file LICENSE for the full text and file GPLv2 for list of all authors).
Some portions are licensed under LGPL version 2 or later (see file LICENSE.LGPL for the full text and file LGPLv2 for list of all authors). These are the files which might be later used to create a library, useful for all engines as well as any other future third-party projects.
Each source file should have a header describing its license (GPL or LGPL) and precise list of contributors. If no such header is present, GPLv2 (or later) is assumed, as described in files GPLv2 and LICENSE.
Russian-language documentation is available at [[docs/ru/]]. English documentation not available yet, sorry.