HP-UX and IRIX (SGI) are on a "slow retirement" plan. The number of users is decreasing regularly and eventually I expect that we may stop supporting these systems, although it depends entirely on demand. For some types of licenses, we charge more for these two systems than for other unix systems. This being said, HP-UX does power the largest unix LISTSERV site in the world (by number of subscribers), which is the second largest if you ignore operating systems. LISTSERV works very reliably under HP-UX. We ran into all kinds of annoying HP-UX specific problems, but they have been solved years ago and now the product is very stable. There is no technical reason to avoid HP-UX, it's just that it is losing market share rapidly (at least for LISTSERV). Eric