I was just listening to Gabby Davis do a great job explaining all things Sametime on the "This Week in Lotus" podcast, when the question was asked... "What is an IFR / Interim Feature Release?". This has come up in a couple of different venues, so I thought I'd explain. And no, we don't just sit around thinking up new acronyms to confuse all of you. :-)
As you can imagine, an organization the size of IBM Software Group has a handful of rules about what can go in a given release. New functionality can go into "major" releases (ie: 8.5.2) but not into "minor" ones, fix packs or the like. Major releases also have very specific, intentionally onerous and time consuming testing requirements. By calling it 8.5.3, we wouldn't have been able to ship until next year.
The IFR mechanism, while not commonly used by ICS, is regularly employed in other Software Group divisions. Through it, we could deliver new capabilities as a bolt-on to the existing release and limit our testing to the just new components. While a mouthful to say, 8.5.2 IFR 1 probably shaved 6 months off our ship date. I'm oversimplifying and IFR's are intentionally difficult to get approved... but we thought there was some really good functionality here and we wanted to get it to you as quickly as possible.
Hopefully, that helps. Enjoy!