[vacri]

http://mozilla.debian.net/ is probably what you're after.

Debian uses the 'ESR' versions (long-term support, for enterprises etc) of firefox as it's stock browser, as it's impractical to review the latest and greatest every few weeks for security. The above link gives you the appropriate lines to add to your apt sources.list to get whichever version you like for whichever flavour you're running.

This gives you Iceweasel though, not Firefox, however the only difference is the branding.

[shmerl]

Yes, I know about that. I'm using Debian testing, so for me that page redirects to unstable and experimental anyway, and I don't really want to mix with those. In the past the difference was more than branding, so I'm already used to sticking to stock Mozilla builds.