Well, I don't think there is any hardened rule or RFC on this but there a standard as far as what your versioning is supposed to mean. That of course being the all-known major.minor.minor_minor.etc. However, I believe that the versioning is really up to the developer. It's ultimately up to you if you want to name your first version of a program as version 5. I wouldn't really recommend that but how is the end user supposed to know? I believe it really is just a way for the developer(s) to maintain the code and to be able to handle revision control a little easier. I have seen some people release their first versions as 0.x probably in anticipation of coming out soon with a better version or perhaps that is just how they want to version their software.

Some people let their revision control software do the versioning for them. eg. RCS or CVS. I like this because unless you tell the revision control to version your rev differently it just minors it up one (ie 4.1 to 4.2 etc).

In summary, I believe it is up to you. That's how I've done mine. And I do my versioning with the intent to be able to control my revs a bit better.

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- Jim