That page is way out of date. There&#x27;s not really much IIS does other than hand off requests to a new or already warmed up php-cgi.exe (via the FastCGI bits). The performance stuff is really more down to the PHP maintainers (though Microsoft have contributed, and continue to do so).<p>The only pain point can be when there&#x27;s a new release of PHP and you have customers who want to access MS SQL databases. This is done via Microsoft&#x27;s own drivers [0] (Windows only). It&#x27;s not been unknown for these driver releases to lag a bit behind PHP releases, but that said I see they&#x27;re on the ball now with support for 5.6.<p>Other than that PHP runs just as quick and as reliably on Windows as it does on our Linux shared environments (I look after both).<p>[0]: <a href="https:&#x2F;&#x2F;www.microsoft.com&#x2F;en-us&#x2F;download&#x2F;details.aspx?id=20098" rel="nofollow">https:&#x2F;&#x2F;www.microsoft.com&#x2F;en-us&#x2F;download&#x2F;details.aspx?id=200...</a>