The following post is inspired by Mickael Istria's recent blog, Call a spade a spade, and a Nightly a Snapshot.
When I was doing builds for the Eclipse Modeling Project, I-builds were weekly published nightlies -- same level of stability as a SNAPSHOT (to use Maven parlance) or nightly, but published on a weekly schedule to bridge the gap between nightly/daily/SNAPSHOT/CI builds and the every-6-weeks milestone releases. The goal was to provide something stable enough for early adopters to grab once a week, but without the non-stop flux of nightlies. Regardless of the label on the build, the process was the same: tag CVS, then build using that tag.
The Final/GA/Release ("R") builds were done as simple renames of the last good milestone or release candidate build, so as to ensure binary-compatibility w/ the last-tested milestone/RC. The same was true for "M" and "S" builds -- they were just renamed "I" builds, and the letter was there simply to differentiate between a maintenance build (M), a stable milestone (S), or release (R).
Branching only happened when a release was done and it was time to produce the maintenance stream vs. the ongoing next-year-release. Sometimes branching would happen AFTER the x.y.1 maintenance because it saved duplication of commits in the x.y+1.0 and x.y.1 streams.
Now at JBoss, we publish "nightly" builds, which are keyed to SVN changes and therefore could be as often as hourly or as infrequent as weekly, depending on what's happening in the repo.
We also do milestone builds about once ever 6-8 weeks (similar to the Eclipse.org release train schedules), which is more carefully vetted, tested, and QE'd. It is produced using the same *process* as the nightlies, but are named differently and pulled from a freshly-created stable branch in the repo (so its degree of change/churn is less). (Branching happens right before every milestone or release candidate so that hardening/stabilization/documentation can happen in the branch while trunk stays open for new development.)
Bottom line -- I've only ever needed three types of builds, regardless of nomenclature or labelling differences. And of these 3, the last 2 are the same thing but renamed to underline the build quality/stability:
* nightly/CI/integration/weekly/SNAPSHOT build (unstable, for bleeding edge adopters)
* development milestone (probably a re-christened nightly; stable, early adopters)
* stable release / Final / GA (probably a re-christened milestone; release quality)
So... does it matter if it's called nightly, integration or SNAPSHOT? or Stable, Milestone, Maintenance, Final, GA or Release? As long as it's easily reproducible (yeah, Tycho!), what's in a name?