Compiling the plugin works for me on Arch Linux x86_64 or OpenSuse 11.2 x86_64 & FF36: " mkdir gwt-source cd gwt-source svn checkout http://google-web-toolkit.googlecode.com/svn/trunk/ trunk svn checkout http://google-web-toolkit.googlecode.com/svn/plugin-sdks/ plugin-sdks cd trunk/plugins/xpcom export BROWSER=ff36 export DEFAULT_FIREFOX_LIBS=/usr/lib/xulrunner-devel-1.9.2/sdk/lib/ make clean make " This shoulds create "gwt-dev-plugin.xpi" in prebuild directory, open it with FF and may the force be with you.
Update: This reciept also works under Ubuntu 10.10 32bit (you don't need to export DEFAULT_FIREFOX_LIBS)
See original comment:
Issue 4141 - google-web-toolkit - Various compatibility problems with OOPHM Firefox plugin on Linux distros - Project Hosting on Google Code