Fennec Windows Mobile Pre-Alpha Problems

When we released the Fennec pre-Alpha for Windows Mobile, we hoped it would help us find bugs that didn’t show up on our test devices. We knew there would be problems lurking around so we wanted to get a preview version into the hands of more testers. The good news is we found a showstopper! The bad news is the browser is basically useless for many people.

The Short Version

We are digging into the problem and have been able to reproduce it internally. It’s obviously a top priority and we will get a new version released as soon as we get a fix in place.

The Long Version

When Fennec loads, many people are left looking at the background checkerboard pattern. This appears to be memory related. Windows Mobile has some exciting restrictions around memory use. There are ways to get around the restrictions and that’s what we are working on. When we figure out the true cause and get a solution in place, we’ll be sure to blog the details.

Follow the bug to monitor our progress. We hope to have a new version out soon and you can help us find more of the other bugs.

Oh, one other issue that has come up a few times: Fennec for Windows Mobile is currently targeting ARMv6. So older ARMv5 devices won’t work in this release. We are working on that too.

Thanks for your patience and thanks for testing.

Fennec & Gestures

Felipe Gomes has been busy. We talked on IRC a short time ago about adding a gesture engine to Fennec. He made a video of the current version. The results are very cool. His work is being tracked in bug 476425. The engine is currently packaged as an extension, so you can play with it yourself. Just pull from Felipe’s repository and put the code inside your extensions folder in your profile.

Go digg it!


The newest official XULRunner has been released. XULRunner matches the Firefox 3.0.6 release. For XULRunner developers, most of the changes in are related to security fixes. You can also look at the full list of fixed bugs.

Source tarball

Update: We now have XULRunner builds for Windows Mobile! XULRunner runtimes now exist for Windows, Windows Mobile, OS X, Linux and Maemo (a mobile Linux). Another XULRunner port is underway: Symbian OS (S60).

Want to get started building XULRunner applications? We have an article for that.

FOSDEM 2009 Wrap-up

FOSDEM 2009 is over. Once again, there was a lot of great stuff happening. I managed to leave the Mozilla Room once or twice to see other sessions. The Mozilla Room sessions were very good and not just because I was in two of them. There were so many people trying to get into the Mozilla Room, we had to stop people from coming in.

I posted the presentations of my Fennec and Embedding sessions. The Fennec session has a companion wiki article as well.

Paul Rouget moderated a spirited discussion on creating XUL communities. The group created a lot of good feedback for Mozilla and for themselves. I really hope we make some progress on the action items.

DOM Inspector for Fennec

DOM Inspector is a great tool for debugging XUL, HTML and CSS. DOM Inspector 2.0.3 now supports Fennec (1.0a1 – current). To install in Fennec:

  • Go to the Add-ons Manager “Get Add-ons” pane.
  • Type “dom inspector” into the search box.
  • Press the “Add to Fennec” button.

There is currently no visible UI (menu or toolbar) to launch DOM Inspector, but you can use CTRL+SHIFT+I to open the inspector window. Using DOM Inspector should make porting add-ons to Fennec a little easier. Tested on Fennec desktop and n810.

Fennec – The Inside Story

No, I’m not dishing dirt on Stuart. I started to put together some Fennec front-end documentation. Fennec is similar to Firefox, but very different at the same time. Some background information and discussion of the internals is probably a good thing.

I also pulled in some performance related guidelines, most of which I discussed in this post. The document will become the core of my FOSDEM Fennec talk. If you’re thinking of attending that talk, read the document first and come prepared with questions.

I want to add sections on JavaScript APIs and events available in Fennec, as well as some of the process flow. Add-on developers, in particular, should have a solid understanding of the internals. It will make porting your code easier.


I’ll be making my second trip to Brussels to take part in FOSDEM. I had a lot of fun last year and I’m looking forward to another great conference this year. I have two sessions in the Mozilla developer room this year:

  • Mobile/Fennec – My part of this talk will cover how Fennec is built, building add-ons for Fennec and some performance-related coding tips.
  • Embedding Mozilla – This talk will cover what’s been happening with the new Mozilla embedding APIs.

If you have ideas for topics you’d like me to cover in either of those sessions, let me know.