The Mozilla team had been working on a 64-bit version of Firefox for Windows for a while. The project has been riddled with a lot of issues as a result of which, Mozilla’s managing engineer Benjamin Smedberg has announced that he is pulling the plug out.
Mozilla had many reasons to work on a 64-bit browser for Windows. Firstly, its rivals, notably Internet Explorer and Opera, offer 64-bit browsers. This allows these browsers to make use of more than 2 GB of memory. Firefox, on the other hand, is 32-bit, so it has to limit itself to 2GB of memory.
Google’s Chrome is also 32-bit only but it deploys a clever trick whereas it treats each of its tabs as separate processes. This allows it to make use of more than 2GB of memory.
However, the odds have been weighed against the Mozilla team in developing a 64-bit Firefox for Windows. The team has faced a whole range of problems such as a sheer lack of stability, lack of many plug-in options, problem in distinguishing between bug reports generated by the 32-bit and 64-bit users and more.
The fact remains that a 64-bit browser for Windows is not all that important and will cater to a rather small portion of users. Nonetheless, nearly 50% of Mozilla nightly testers had been working on the project and now that it is being shelved, it may cause feelings of resentment among them. Nonetheless, Mozilla is continuing work on the 64-bit version for Linux.
Source: Mozilla Developers Forum