When Firefox 3.5 came out, I along with many others, was eager to try it. For a while I ran it out of the archive directly but this caused minor issues as it’s a messy solution. At some point I noticed firefox-3.5 in the repository: tyler@quadjutsu:~$ apt-cache search firefox |grep 3.5 abrowser-3.1 - dummy upgrade package for firefox-3.1 -> firefox-3.5 abrowser-3.1-branding - dummy upgrade package