At this time Mozilla are not developing a version of Firefox for Windows Phone 7. For details see http://blog.pavlov.net/2010/03/22/stopping-development-for-windows-mobile/

Firefox is now available on Windows Phone 7 here is the link  :

[Link to unofficial download removed by moderator. Please read Mozilla Support rules and guidelines, thanks.]

Be aware that it is not an official release from Mozilla and is not free.

This is not mobile Firefox for Windows Phone 7 as it is just a wrapper that uses the phones native browser engine as per description.

Also a discussion at http://forums.wpcentral.com/marketplace-apps/192074.htm

You're replying to a thread that is over a year old. You should use https://support.mozilla.org/en-US/questions/new where volunteers can get more details about your setup.

Because this thread is so old and more people might start using it for their own questions, I'm going to lock it.