Forum OpenACS Development: Re: Lists and theme zen - Release Version Numbering
Branching would've greatly complicated things, delaying them, adding a merge step most likely (5.3 -> 5.4 [say] -> HEAD), etc etc.
So the OCT decided we'd stick with the 5.3.1 designation for core. We weren't that happy about it, because we saw that if we'd been smarter we could've predict that the scope of the change for core was going to be larger than we first thought.
We did, of course, move .LRN from 2.2 to 2.3 because of the size of the change. It was obvious moving to the zen theme there was going to be huge.
Keep in mind that we were all learning about accessibility standards as we did the work. I think the team did an incredible job (not me, the team, I did very little of the work other than dotlrn-specific stuff like new-portal).
The change isn't significant enough to warrant a 5->6 or 2->3 change IMO. We're just changing some CSS and HTML. It's not like we're adding ajax or xotcl to the core ... There is no "fundamental change in the architecture of the system". The changes are noticable because they're in HTML and CSS so the user sees them. The user would see a trivial change like deciding all text should be surrounded by H tags, too, but that wouldn't be a "fundamental change in the architecture of the system", right ???
The next core release will be 5.4, because we'll be completing Lee Denison's revamping of the API for placing stuff in the HEAD section, etc. That's much more major than our relatively small CSS/HTML changes for lists etc.