We had some progression with Firefox. Now we like to have Thunderbird v3 too. The main issue was the "-Os" compiler option. And that the binaries compiled with Ubuntu 9.10 PowerPC weren't portable to Debian 5 PowerPC and didn't terminate as expected. But we have a backup system running Debian.

Using the Apple PowerBook G4, Debian GNU/Linux 5 PowerPC and the Thunderbird sources, I have compiled Thunderbird without an error. And even use the package with Ubuntu 9.10 PowerPC. And now how it will work:

As it takes some time to get the sources, start downloading them now. And read on while the bits are gathering on your side. The sources are located at ftp://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/3.0/source/, get the file named thunderbird-3.0.source.tar.bz2. Or use this link, perhaps you need to "right-click" on it to get the file: ftp://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/3.0/source/th...

To make sure you meet all the request for building Firefox, please read on: http://developer.mozilla.org/en/docs/Linux_Build_Prerequisites

If you run Debian you might solve all dependencies with the following two commands:

apt-get build-dep thunderbird
apt-get install libdbus-glib-1-dev curl libcurl4-gnutls-dev libidl-dev libasound2-dev mercurial mercurial-common libiw-dev libnotify-dev

After the donwload is completed, extract the files into a folder you like and you will remember later on. The folder isn't called Thunderbird but comm-1.9.1. "cd" into it. Put the following lines into a file that is named:
.mozconfig (yes the first character is a point, it will disappear when you use only "ls", but is seen wenn you use "ls -a")

The content is:

ac_add_options --enable-application=mail
mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/tb-opt
mk_add_options MOZ_MAKE_FLAGS="-j2"
ac_add_options --enable-calendar
ac_add_options '--enable-optimize=-O2 -g' 
ac_add_options --enable-static 

Bring up a shell and start the following command:

make -f client.mk 

If you like to test the binaries before you pack them start comm-1.9.1/tb-opt/mozilla/dist/bin/thunderbird. To build a package you have to cd into comm-1.9.1/tb-opt. Issue the following command:

make package

Your archive thunderbird-3.0.en-US.linux-powerpc.tar.bz2 will be located in comm-1.9.1/tb-opt/dist.

If you trust us and don't like to waste time, you can use our binaries:
Thunderbird Version 3.0 Community Build: thunderbird-3.0.en-US.linux-powerpc.tar.bz2
[Link fixed. I thought I have checked everything, but ... I am human in the end. My thanks to adams for the hint.]

You will get a folder called thunderbird, when you unpack our archive. Move it to your home folder or into /usr/local/bin/. You can create an application starter by pointing it to your chosen path and to the script thunderbird/thunderbird. Please don't start thinderbird-bin.

That is it. Have fun! If you like, leave a message on which distribution and hardware you are using our binaries.