Starting with version 5.0, SCS includes support for using PHP to build custom sites. This is made possible through the use of Phalanger for .NET.
We have a new SCS starter site that uses PHP pages and the Smarty template library as an alternative to ASP.NET's ASPX/ASCX.
This is not the standard PHP in the LAMP stack, though PHP developers will feel mostly right at home building PHP pages that use our Smarty templates.