Monday, May 31, 2010

Pre-release Firefox Windows 64-bit builds now available (testing purposes)

We started producing on Friday in an automated manner the 64 bit version of Firefox for Windows.

The purpose of automating these pre-release builds is to allow developers to do work for this architecture and for  testers to use the builds and be able to file bugs. Currently, we are producing these builds twice a day and upon request from developers.

If you go to:
NOTE if you want to run the builds and you don't have Visual Studio installed you should install the Microsoft Visual C++ 2010 Redistributable Package (x64) to be able to start Firefox, otherwise, you will get a message saying that MSVCR100.dll cannot be found. Let me know if this works for you.

You also have to note that Flash is not yet available for Windows 64 bit builds (currently only available for Linux).

If you want to know what the big picture currently is you can visit this page:

This was pre-announced last week in our mailing list and by Oduinn in his blog.

Creative Commons License
This work by Zambrano Gasparnian, Armen is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.


  1. The workaround worked, but… can't you deploy that library with Firefox?

    I have Win7 ultimate 64bits with all patches and I didn't have that library. Maybe a code that checks for that library and suggets to download it before using Firefox should be added, as VC2010 is not in every computer nowadays.

    Anyway, congrats for the effort!

  2. hey willyaranda,
    I have just filed the bug covering this issue.

    Somebody should be able to get to it and fix it.

    Thanks for testing it and for verifying it and gracias for the congrats!

  3. Do you think Adobe will release an x64 build of Flash any time soon as a result of this?

  4. @sciguyryan we would just be speculating. You might want to wait an hear back from stshank is also a good source for an opinion to be taken under consideration

  5. Are there no plans to allow x86 plugins to run in x64 Firefox? It seems like it should be possible using Electrolysis/OOPP by shipping both 32-bit and 64-bit plugin containers, but I'm not an expert.

  6. @MikeN we are now two in the filed of not expertise ;)
    You can bring up these excellent questions to and there should be people who can answer them.

    Cheers and thanks for commenting,

  7. Any advantages (speed, etc) to using the 64-bit build? Or is it the same as 32-bit just "fancier".

  8. @Marcus I just taken care of automating it. You might want to ask on the where you might find people running different test suites.

    Thanks for commenting.