run code in 200+ php & hhvm versions
Bugs & Features
<?php $variable1 = 2; $variable2="6"; echo $variable1+$variable2; //echoes 8 echo $variable1."6"; echo "<br/>": echo $variable1.$variable2;

Here you find the average performance (time & memory) of each version. A grayed out version indicates it didn't complete successfully (based on exit-code).
Note: hhvm uses a JIT which only kicks in after a few runs. Since we run scripts only once, hhvm always runs slower.

VersionSystem time (s)User time (s)Memory (MiB)