Mozilla has released Mozilla Developer Preview 3.7 alpha 2.
It’s necessary to first talk about the name. I think this is the first time Mozilla is using this kind of quirky name for a development release, which reflects it is still not clear what we have here or when we’ll have it. The main goal for this release is to test the out of process plugin (OOP) architecture that allows plugins to run on their own process, improving overall Firefox stability and security.
A few weeks ago, Mozilla announced OOP would come as a minor update (code named Lorentz) to the current 3.6 branch. This developer preview however comes from the trunk (Mozilla’s main development code repository) as OOP hasn’t being ported to the branch yet.
OOP is available only on Windows and Linux at this time and you can see it in action via Windows’ process manager where every running plugin is listed as mozilla-runtime.exe. For example the screenshot below shows Silverlight, Flash, and Foxit Reader running in three different processes. Also note that even as I’m playing two YouTube videos and have several PDFs opened at the same time only one process is created for each plugin. So yes, it means if a plugin instance crashes, all instances do as well.
Here’s how it looks when a plugin (Foxit Reader here) crashes. As you can see the rest of the page is there, as is Firefox. Just the plugin area is grayed out and you can click on a link to have the page reloaded.
As Mozilla’s Benjamin Smedberg explains, it is possible to force a frequently crashing plugin in process (along with Firefox code) by creating an advanced preference like dom.ipc.plugins.enabled.nppdf32.dll and setting it to false, replacing the last part with the appropriate plugin library name.
I hope this could happen automatically, so if Firefox detects a % of crashes above a certain threshold (say 30%) it will automatically set the preference and save users a headache or two.
Also worth noting in this release are the first steps of the big Windows theme update which looks very good so far.
Also the bugs that prevented correct tab preview from Windows 7 task bar on Firefox 3.6, seem to be ironed and it works perfectly now.
However, these last two features will most likely come as part of Firefox 4.0 as planned.