This document discusses using HHVM as a drop-in replacement for PHP to speed up Magento webshops. HHVM is a just-in-time compiler created by Facebook that translates PHP to bytecode and machine code, resulting in performance improvements of 5-10 times over regular PHP in some cases. While HHVM is not fully compatible with Magento, over 100 fixes have been contributed to HHVM to address Magento-related bugs. Benchmarks show significant improvements in response times and higher transaction rates when using HHVM with Magento compared to PHP.