EA 0.94 & PHP 4.4.1 stable on IIS 6 by Dominic Ryan
I'm still stuck with PHP 4.4.x due to some legacy codebases that I hope to be rid of by mid this year, but I have found using EA 0.94 with PHP 4.4.1 in FastCGI mode on IIS6 to be very stable and very quick. I had been using APC 3.0.11 for a while, but it was crashing several times a week. I'm yet to try xcache.
I'm running a variety of PHP based web apps such as Drupal, Xoops, Gallery2 and RoundCube. I've developed a PHP installer for IIS that utilizes PHP 4.4.1, FastCGI and APC opcode cache (although I'm thinking of dumping APC as I can't seem to get it stable under the 4.4.x branch). It's a free download and is a good choice for small to medium website operators wanting to get maximum speed out of PHP on IIS;