Hi.

I use the Gnome GlobalMenu, the application that hides the menu bar in the program windows an displays it in a panel instead. One problem is that it only works with Gnome programs, so that Firefox and Thunderbird are not displayed. For Firefox however, there's this addon: http://www.mediafire.com/?bumyci36q7wbh17, solving the problem.

Should it be that difficult modifying that addon to work with Thunderbird? Does anyone here have knowledge about how to modify Mozilla stuff?

xpi is basically a zip file.
In it there's a plain text file called install.rdf. It follows an xml schema I believe. Anyway you can modify the version (min version/max version) and software that the installer works with.

If you don't know what the thunderbird install.rdf is supposed to look like then I would download a thunderbird add-on and compare the two.

You might get lucky, change the version information, and have it "just work".

Let us know how it works. Rezip it by

Now I actually have the addon I need, except that it's tar.gz and can't be installed in Thunderbird...

So untar it. Look up untar .tar.gz

Yes, that's the first thing I did, but then...? What do I do with the extracted folder that Thunderbird can't even see?

Well what did you download? I'm not sure I understand what you're trying to do. Based on the link you gave and the instructions I gave you it dealt with an .xpi file.

What did you download that gave you a .tar.gz? .tar.gz is an archive and not specific to mozilla (kind of like how a zip file isn't specific to mozilla).

You have to build it into an xpi file from the source since xpi is the installer format Firefox and Thunderbird understand. First you need to read the README. The README says check the INSTALL file for build instructions. The INSTALL file says you need libxul and gtk+-2.0 before building. So install them.

Then follow the instructions within INSTALL to build it. In the terminal browse to the folder of the extracted .tar.gz.

Also as I said before you need the zip and unzip packages installed because that's what an XPI is. I just summarized my google searching. Searching for stuff like "libxul ubuntu" and "gtk+-2.0 ubuntu" will get you where you need to go for future reference.

I can't install those dependencies. Hopefully Ubuntu will solve these problems in the future, or if Mozilla works something out.