Earlier this week Microsoft release a PHP driver for SQL Server. You can download it from http://www.microsoft.com/downloads/details.aspx?FamilyId=61BF87E0-D031-466B-B09A-6597C21A2E2A&displaylang=en Documentation is available online at http://msdn.microsoft.com/en-us/library/cc296221.aspx. There is a team blog at http://blogs.msdn.com/sqlphp/ and a community forum at http://forums.microsoft.com/MSDN/ShowForum.aspx?ForumID=2108&SiteID=1
The SQL Server Driver for PHP represents a new way for Microsoft to help developers access SQL Server from non-Microsoft development environments. The driver is a thin C++ wrapper on top of the Microsoft SQL Server Native Client ODBC driver, translating the PHP calls into ODBC API calls. This approach simplifies development and reduces the surface area from a security standpoint. In the future, we could build drivers for other languages (Ruby, Python, etc.) using this same approach without having to duplicate the low-level client interfaces. By making the source code for the PHP driver available, we are providing a blueprint to communities that do not yet have Microsoft-built SQL Server connectivity to show how they can access SQL Server via our ODBC driver.
The source code for the PHP driver is available from the codeplex site http://www.codeplex.com/SQL2K5PHP