What do the numbers in a release version mean?
- 1.x.y.z? And why is it sometimes 1.x.y(z)?
- For example, version 1.21.6(99587)
These version numbers follow a common convention in software engineering of four numbers. The common definition of w.x.y.z-style release numbers is Major.Minor.Patch.Revision.
Using that terminology, Second Life has only had one Major version change - from 0.x beta to 1.0 release. As Second Life is a constantly evolving service and platform rather than a traditional monolithic software application, we have no current plans to increment the initial number.
.x (Minor) and .y (Patch)
- Linden Lab uses the second digit x to denote a substantial new feature or sizable release, for example:
- 1.10 introduced flexi prims
- 1.11 was a revamp of the UI layer
- 1.12 had groups and estates improvements
- 1.14 introduced render pipeline improvements
- 1.20 introduced a "Silver" skin for the user interface
- 1.21 introduced the ability to save scripts with the Mono scripting engine
- 1.22 was a maintenance release with many bug fixes
- and so on.
- (The SLHistory Wiki http://www.slhistory.org/index.php/Release_Notes has unofficial archives of the release notes.)
- In between these Minor 1.x versions are any improved builds (small iterations of little bug fixes) denoted by the third digit .y.
- Most often, while a Minor 1.x version is in its beta or Release Candidate RC status, it will undergo 3-6 such build iterations. Thus it will typically become "official" with a number like 1.20.6.
- EXCEPTION: In the versions from 1.15 to 1.19, Linden Lab switched to having the second digit (e.g. 1.19) denote a new viewer which was a mandatory upgrade for Residents, to go along with a server-side upgrade. Thus, from version 1.15 to 1.19, the in-between 1.x.y versions were any optional upgrades denoted by the third digit, y -- even those with substantial new features -- such as 1.19.1 introduced WindLight atmospheric rendering.
The final digit always represents a unique Revision number, which denotes internal changes only. The official released version of the Second Life viewer will only use the first three digits to have meaning (e.g. 1.20.6).
- Some parts of the Second Life UI and Web site show this last digit in parenthesis (z) to emphasize the, er, parenthetical nature of that field - it shouldn’t be important except to software developers seeking a precise snapshot of when the code was packaged.