On many Linux distributions by default there is only Firefox 3.6. However, when I try to install Convergence I get:How can I install Convergence on a distro that runs Firefox 3.6 (e.g. Scientific-Linux 6.1 or Ubuntu 10.04 LTS)?
Convergence with Firefox 3.6?
firefox;ssl
According to this: FF Version Compatibility Info Needed, you can't run that add-on on Firefox 3.6. You'll need to get Firefox 4 or above.