My machine runs on Arch Linux and it is a rolling release. Mozilla updated Firefox browser from 56 to 57 a few hours ago. I checked the Arch channels and it was in Testing for a while. But now I've been notified it is ready for users. Yes it is fast. Some extensions are not ready yet. I hope their developers release their compatible versions soon.
Previously ranted about the blind alley Ubuntu 11.04 seemed to be leading us when it comes to some applications not being ready yet for the dropping of system tray. What I should have done is press on. There are posts about editing a white list with a recommended GUI tool to help us out here , here and here . Like everything in Linux, there's a configuration file for it, if you can find it and if you have the inclination to go ninja. If not then there's dconf-editor. Download dconf-tools from Software Center. Navigate to desktop>unity>panel. Add your application in the white list. Then close the window. No save button. mmm. So far I have added Shutter, Dropbox and Keepassx in the white list. Before... After.

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