What Software Version Numbers Really Mean Author Unknown Once you start playing with software you quickly become aware that each software package has a revision code attached to it. It is obvious that this revision code gives the sequence of changes to the product, but in reality there's substantially more information available through the rev-code than that. This article provides a guide for interpreting the meaning of the revision codes and what they actually signify. 1.0: Also known as "one point uh-oh", or "barely out of beta". We had to release because the lab guys had reached a point of exhaustion and the marketing guys were in a cold sweat of terror. We're praying that you'll find it more functional than, say, a computer virus and that its operation has some resemblance to that specified in the marketing copy. 1.1: We fixed all the killer bugs ... 1.2: Uh, we introduced a few new bugs fixing the killer bugs and so we had to fix them, too. 2.0: We did the product we really wanted to do to begin with. Mind you, it's really not what the customer needs yet, but we're working on it. 2.1: Well, not surprisingly, we broke some things in making major changes so we had to fix them. But we did a really good job of testing this time, so we don't think we introduced any new bugs while we were fixing these bugs. 2.2: Uh, sorry, one slipped through. One lousy typo error and you won't believe how much trouble it caused! 2.3: Some jerk found a deep-seated bug that's been there since 1.0 and wouldn't stop nagging until we fixed it!! 3.0: Hey, we finally think we've got it right! Most of the customers are really happy with this. 3.1: Of course, we did break a few little things. 4.0: More features. It's doubled in size now, by the way, and you'll need to get more memory and a faster processor ... 4.1: Just one or two bugs this time... Honest! 5.0: We really need to go on to a new product, but we have an installed base out there to protect. We're cutting the staffing after this. 6.0: We had to fix a few things we broke in 5.0. Not very many, but it's been so long since we looked at this thing we might as well call it a major upgrade. Oh, yeah, we added a few flashy cosmetic features so we could justify the major upgrade number. 6.1: Since I'm leaving the company and I'm the last guy left in the lab who works on the product, I wanted to make sure that all the changes I've made are incorporated before I go. I added some cute demos, too, since I was getting pretty bored back here in my dark little corner (I kept complaining about the lighting but they wouldn't do anything). They're talking about obsolescence planning but they'll try to keep selling it for as long as there's a buck or two to be made. I'm leaving the bits in as good a shape as I can in case somebody has to tweak them, but it'll be sheer luck if no one loses them.