Mike Schroepfer wrote:

I wouldn't call this "removal" but rather "fast-path DOM"... and I don't think it's a bucket-A item. I think it could implemented as a much smaller bucket-B item once the actionmonkey (tamarin JIT) stuff is landed.

This is tricky: we could either

* implements XBL2 and keep mozilla-XBL -- this is safe and in bucket two, but has the problem that we're carrying around two significant infrastructures that will interact poorly

* replace mozilla-XBL with XBL2 -- this is probably much easier to implement correctly and quickly, but it involves rewriting our existing mozilla-XBL bindings in XBL2. In some cases we can come up with automatic transformations, but it will still be a pretty huge change that really should be in bucket A above.

Note that several of these tasks have dependencies on eachother: XPCOMGC depends on AM stage 1 and stage 2. Exception support depends on XPCOMGC.

A critical piece of this plan that I think we need to nail is directing our community of nightly testers. It's possible of course to simply have nightly testers on mozilla-central at all times, but I don't think this provides maximum leverage:

* Testers may want to actively follow one of the feature branches: e.g. the UE team will have experiments and ask for testing of those before they hit mozilla-central... an XBL2 branch will want testing from extension authors and interested developers before it is merged to mozilla-central.

* We don't want to orphan a nightly tester: if they have been testing a nightly from the UE branch, we'd like to keep them up to date nightly. If the UE branch stops being developed, we want to repatriate that user to mozilla-central

I think we can accomplish this through the update system and major update offers:

+-------------------------------+ | Minefield Update | | An update is available. You are currently using | the Minefield stable nightly builds. We are looking for | testers of the user experience branch. This branch contains | experiments in the user interface design of Firefox. Would you like to | update to the UE branch? | | [ Update ] [ No thanks ] | +-------------------------------+

Finally, I think that it may make sense to do an alpha every 4 weeks. I know that mconnor has been planning a monthly cadence for new UE features, and with an always-stable mozilla-central and release automation, I think we can schedule the alphas more frequently than we have. But I think we should make sure that we get automatic updates from alpha->alpha so we don't leave people stranded.

--BDS