Making it work with FF13 Rated 5 out of 5 stars

It's fairly easy to get this working with FF13.

- Go to and download Pencil-1.3-4-fx.xpi
- It's a zip file, so rename it with a .zip extension and unzip it
- Edit the file application.ini and change the value of MaxVersion to something like 13.* (or a higher number to avoid it being deactivated by an update)
- Save the file, and zip up all the files. Then rename the .zip to .xpi
- Drag and drop the .xpi file onto FF. It'll install as normal, then when you restart Pencil will be installed.

It appears to work OK as far as I can see, but of course YMMV.