Name collision--QNX's gui was/is also named "Photon MicroGUI" and that is what I thought this post was going to be about: http://www.qnx.com/developers/docs/6.5.0/index.jsp?topic=%2F...
Can confirm. Came in expecting the other Photon MicroGUI ("now there's a name I've not heard in a long time"), was surprised/disappointed. Man QNX+Photon made for a nice GUI operating environment. Rivaled only by BeOS on my "GUI environments/systems I wish had made a bigger splash" scale.
Those were the days! I had BeOS as my only OS for over a year until it became clear that Palm wasn't going to continue supporting and updating it. It wasn't long after that I got into QNX, initially because of my interest in embedded systems, but after running Photon on a test machine I fell in love with it almost as much as I loved BeOS.