version numbers : Java Glossary

What is a Version Number for?

• It lets the end user know if she has the latest version of some software.
• It lets the end user know if she an update were something minor or if it were substantial.
• It lets the end user know if she will likely be expected to pay for an update.
• It lets the end user report precisely which software she was using when she noticed a bug.
• It gives the end user an idea of how old her software is.

How Not To Do Version Numbers

• Firefox updates from version 26 to version 27 even when nothing at all of consequence has changed. This is deceptive.
• Flash has version numbers like 13.0.0.214. That is not a number that users can think about or remember.
• It gets confusing with version numbers like 20.12. Is that more recent or older than 20.9. If you use fractional version numbers, always use the same number of decimal places. 20.9 becomes 20.09 or 20.90.

The Release Date

The release date is far more meaningful than the version number to end users. They remember approximately when they last updated. If they look at the release date and see it was two years ago, they can be pretty sure there will be an update available. If they see a file sitting on their disk, the release date lets them know if it is likely obsolete.

Beta Version Numbers

Sometimes you prerelease an experimental version e.g. 7.45beta. When you issue the official code, make sure you increment the version number so improved later code always has a higher version number, e.g. 7.46.

Build Number

If you make a minor bug fix to your common library, refactor some code, tidy some code, rename some methods, the end user should notice nothing. Increment the integer build number each time you clean compile everything, even when you do not do a release.

Suggested Rules

• If the software has a fee for update, increment the version number to the next highest integer only when the major update/upgrade requires a fee.
• For minor updates increment by 0.1 if you have 10 or fewer releases between major updates, or 0.01 if you have up to 100 releases.
• Always include the release date and build number along side the version number in any place you post the current version number.
• Put the version number, the release date, build number and the update URL (Uniform Resource Locator) in the About box

Document Versions

In future, documents will come to be treated more like programs when it comes to tracking versions. For example:

• documents will have embedded electronic version numbers.
• When you go to read a document, it will check to see if the version you have is up to date. If not, it will arrange for a packet of just the necessary deltas (compressed changes) to be sent from a local cache or from the author.
• If you EDI (Express Deep Interest) in a document, deltas will be pushed to you immediately the changes are made. That way, when you go to read the document, it will already be up-to-date. There will be no delay to fetch the deltas. You must redo your EDI from time to time or it will expire.
• Public documents will be archived, so it will always be possible to see what earlier versions looked like, even if the author has withdrawn them.
• The work is mostly low priority, it could be scheduled when the Internet is not busy.
• We will come to appreciated the danger of using an out-of-date document and not knowing it.