HipHop compiles the script natively, while KittenDB seems to converts to C++ and then compiles it. KittenDB seems to have fewer dependencies, meaning it's likely to be less feature rich. This could be down to the fact that HipHop is actually a full stack, while this is just the interpretation layer.
I'm finding it difficult to find any more details because the documentation is in Russian.
I'm interested in the fact that both Facebook and the Russian equivalent independently started work on the same basic idea. It's almost like convergent evolution.
The original version of HipHop also compiled to C++. Very slow to compile C++ actually. HipHopVM is the one that compiles it natively, it's a successor to the original.
It requires additional dependencies because HHVM has to emulate most of the core PHP extension functionality to be compatible with PHP, for example 'mysql_query', etc.
As HHVM is more performant than HPHPc, it's a more relevant comparison. Even then, it's not entirely apples-apples since HHVM supports (almost) the entire language, whereas kPHP seems to only support a subset. Doing so likely lets them make a lot of performance optimizations you couldn't make otherwise.
Nice downvotes. Someone doesn't like the truth. VK basically ripped Facebook verbatim. Now Telegram or whatever its called. They are basically the Russian version of the Samwer brothers.
The downvotes are because no one cares about whether VK ripped Facebook, and your comment is nonsensical.
If this project is not based on the source code of HHVM there is no way a conclusion can be made about its features or performance compared to HHVM, regardless of any relation between VK and FB.
I'm finding it difficult to find any more details because the documentation is in Russian.
I'm interested in the fact that both Facebook and the Russian equivalent independently started work on the same basic idea. It's almost like convergent evolution.