The most painful thing for people like me who dropped Firefox 2 long ago to rely on alphas and betas of Firefox 3 is extensions. Extensions have a maxVersion field. Let's say the last official beta of Firefox 3 is beta3 ; the greateast maxVersion available is then 3.0b4pre. When Firefox 3 goes to beta 4, it's upgraded to 3.0b5pre. But not before. Most of the extensions I use on a daily basis are disabled in my Firefox because there are no updates. Seriously, we all suffer from this, in particular with venkman, SQLite manager and other programming add-ons, and I think another way of doing should be found. Here's what could be done for nightlies only, it could be entirely disabled for official releases.

  1. make the nightly accept an extension even if its maxVersion is less than the current version of Firefox IF its maxVersion and the version of Firefox share the same leading numerical value.
  2. in that case, this extension would be listed as "At risk" at startup time in a special alert dialog.

Update:

<db48x> glazou: you do know that you can turn off extension compatibility
checking by setting a pref, right?
<db48x> glazou: extensions.checkCompatibility?
<db48x> it's easy to miss