I’m pleased to inform you that Microsoft has released FastCGI version 1.5 for IIS 6 and IIS 5.1, as per Ruslan’s posting on blogs.iis.net up on http://blogs.iis.net/ruslany/archive/2010/01/18/fastcgi-extension-1-5-for-iis-5-1-and-iis-6-0-rtw.aspx.  FastCGI is the handler for PHP requests on IIS, and now features:

• Monitor changes to a file (php.ini as an example). Will recycle FastCGI processes for the process pool.
• Real-time tuning of MaxInstances setting. Set by default now.
• STDERR stream handling.
• Sending a termination signal to FastCGI processes for cleaner shutdowns.
• _FCGI_X_PIPE_ environment variable for communication between the extension and FastCGI process.
• Relaxed enforcement of response headers syntax.
• Per-application FastCGI process pools. Allows for two different PHP version used for different applications within the same web site.
• Using UTF-8 encoding for server variable values.
• More descriptive error messages
• Changes in default values for configuration settings.

You can get the latest FastCGI module from the Microsoft Web Platform Installer on http://www.microsoft.com/web.

Enjoy!