Hi,
great news indeed!
Wiadomość napisana przez Ori Livneh ori@wikimedia.org w dniu 19 wrz 2014, o godz. 03:39:
You can enable HHVM by opting in to the beta feature. This short animated gif will show you how: http://people.wikimedia.org/~ori/hhvm_beta.gif.
The link to discussion on the experimental features page links to https://www.mediawiki.org/wiki/Talk:HHVM/About instead https://www.mediawiki.org/wiki/Talk:HHVM
Michał