The new and ultra fast HHVM compiler for PHP is out for some time now. The guys at Facebook are doing great work and really making progress. Now they pass tests with 100% for a growing number of frameworks, with Laravel being one of the first few.
At this moment I wouldn't recommend to use HHVM on a production server. You can use it in a fastcgi mode which works the same way as PHP-FPM, but it's a little to early for that to use on your precious websites and applications.
But you can use HHVM right now to make Composer run a whole lot faster, like 5 times or faster. It's great! You can install HHVM very easy now with the pre-built packages and run Composer standard on HHVM using a simple alias:
alias composer='hhvm /usr/local/bin/composer'
Make sure you'll set the path of your composer file correctly by retrieving it using
which composer or
Update: 8 februari 2014
To make the alias permanent you'll have to add it to your ~/.bashrc file and then run