Nightly is a pre-release testing version of Firefox: bleeding edge and not necessarily stable. It is Firefox -- a rose by any other name, and all -- but it is buggy, as all testing software is (I'm using it right now). New Firefox versions are born from Nightly, so when a 64-bit version of Firefox is released, it will have come from Nightly development. Use it for general browsing and send feedback (Tools -> Options -> Advanced -> General) and you will be helping to beta test a new baby Firefox.

The 32-bit Firefox will work on your 64-bit Windows.

The 64-bit builds for Windows are still not yet officially supported as there is still a fair bit of work to be done. The earliest looks to be Firefox 12.0

The Nightly builds are unstable as they are meant for devs and Testers and not new Firefox users in mind and the 64-bit builds have some their own issues that 32-bit builds do not have. These builds are currently more for to test breakage since it is possible to break 32 or 64 bit win builds without breaking the other. These are also tier 2 builds so if the servers for them goes down or a checkin causes breakage then it does not have the priority to get working again right away like the regular 32-bit tier 1 builds.

Also note that the Nightly channels gets a update each day due to frequency of checkins, sometimes twice with a respin.

Firefox on Mac and Linux has had 32 and 64-bit builds since Firefox 4.0

Unless you are willing to be a tester, the Nightly is not meant for general browsing. Also keep in mind that you will need the 64-bit plugins for the 64-bit Firefox as the 32-bit plugins will not work.

Very clear and helpful - thank you very much.

Very clear and helpful - thank you very much.

After the last upgrade of Nightly about 2 or 3 days ago the browser continues to crash even within 5 minutes of opening, nightly sends crash reports and then after awhile I get an Nightly upgrade but it seems that does not solve the problem and I continue to have crashes. I'm running 64 bit Windows 7 Professional with nightly as my default browser.

I would say tell FF20 release the end of this year.

I cannot remember the official Firefox website, which was debating the advantages and disadvantages of Firefox 64-bit versus 32-bit.

Please could you send my message (thread) to the relevant forum if this is the wrong forum?

I didn't fully understand the discussion, but I shall try and remember what it was about, which may assist the Firefox's person trying to solve the 64-bit J.I.T.problem.

1: I have a modified Chillblast.com Fusion Pulsar PC, whose cutting edge technology have already been super seed: Motherboard P8Z68-V Pro Gen3 to Z77, Intel Processor from i7 2600k 3.4GHz to i7 3770k. I also have Windows 64-bit - no problems with running any software. Therefore, I don't think that there should be a problem with the amount of memory with new computers. http://www.pcadvisor.co.uk/reviews/desktop-pc/3308736/chillblast-fusion-pulsar-review/

2: There should be a 64-bit J.I.T. with future applications; 1920x1080p, voice recognition & 3D etcetera I should have known that once again, Microsoft was responsible for the fiasco-The last fiasco Windows Home Premium 64-bit OEM RAM's limited to 16GB instead of at least 64GB (whilst Asus P8Z68-V Pro Gen3 motherboard = 32GB) & Microsoft's Windows Professional/Premium's RAM limit I think is 192GB, which means when the price for 8GB and 16GB falls users will have to buy at least the Professional version to get more than 16GB RAM. http://www.zdnet.com/blog/hardware/ie9-vs-chrome-10-vs-firefox-4-rc-vs-opera-1101-vs-safari-5-the-big-browser benchmark/11890?pg=6

3: The 32-bit J.I.T. must have started off as an 8bit/16bit, why was it increased to 32-bit in the past?

4: Should be possible to input either; manually or automatically using a wizard, to workout whether a PC or software is; 32-bit or 64-bit.

5: The next step is to use a flag-Until, 64-bit J.I.T.'s are created

   A: For example let 32-bit J.I.T. = FJIT=0 and
   B:  "    "      "  64-bit J.I.T. = FJIT=1
   C: If 64-bit then skip program’s; section/line
      – 32-bit shouldn’t lose too much speed
   D: With a 64-bit J.I.T.
      - Reverse the flag to allow the 64-bit to be
      - much faster than any 32-bit J.I.T.

6: I have dealt with the flag, and now the variables should be dealt with

  A: For example a 32-bit PC = (FJIT32= 32-bits) and
  B: 64-bit PC/Software = (FJIT64= 64-bits).

Therefore,

7: 32-bit PC/software would remain as FJIT32= (32-bit)

8: But, I would convert FJIT64=64-bits into 2 (variables)

   A: FJIT32=1st (32bit) part of 64-bit and
   B: FJIT64=2nd (32bit) part of 64-bit

There is probably no need to waste memory and processing time to set the variables to for example, zero before working out whether the hardware or software is; 32- or 64-bit.

Hope this helps.

BT7474 wrote:

I cannot remember the official Firefox website, which was debating the advantages and disadvantages of Firefox 64-bit versus 32-bit.

You can find the feature page at

• wiki.mozilla.org/Features/Desktop/64bit_Firefox_Windows_7

On that page you can find links to the relevant bug reports. Please keep in mind Bugzilla is not a support or feedback forum; read Bugzilla etiquette before deciding to comment there.

For developer discussions, head over to the newsgroups, e.g.

• mozilla.dev.planning | Firefox 64-bit for Windows: what we know