Google Gears on Firefox 3.6 (ArchLinux)
I'm travel by train quite frequently recently and have to rely on UMTS stick for Internet then. But connections are always somewhat flaky because of the train's speed and different network coverage.
In the past I relied on GMail's “Flaky Connection” mode, which automatically switches between GMail's normal online and the offline mode where everything is stored on your local computer and synced whenever there's a network connection.
GMail needs the Google Gears Extension to do that. Unfortunately, Google ceased to support the extension in favor of the new HTML5 local storage features. Firefox 3.6 supports those, but GMail doesn't! And the old extension no longer works for Firefox 3.6 (Namoroka). Instead you get the following message:
"Google Gears" could not be installed because it is not compatible with your Firefox build type (Linux_gcc3).
The Arch Wiki suggests to compile your own version of Gears. But compiling on my EeePC isn't much fun. Luckily someone else did that already and provided the needed XPI. However his build still doesn't work on Arch Linux because of a minor difference in how Firefox reports its build string.
The solution is simple: download the XPI, unzip it and add the following line in install.rdf.
<em:targetPlatform>Linux_gcc3</em:targetPlatform>
When you zip the whole thing again, you finally have an Arch Linux Firefox 3.6 compatible Gears 32bit extension: gears-archlinux-ff3.6-0.5.35.0.xpi