One of the big changes at Wayfair recently was moving all of our storefront code (well, almost all...we're still working on our sessioned code) from Classic ASP (VBScript) to PHP. The company was started in 2002 and at that time ASP was a common technology on the web, and one that our founders were familiar with. After 8 years of working with it, we had pushed it to the limits and decided we'd get more benefit out of moving to a new technology.