
A recent article by Tony Smith from The Register titled "
Mac OS X 10.3 Panther will not be a 64-bit OS" caused a good deal of confusion with many people, including me. It is also caused a
heated argument here on OSNews. The basic point of the article is that Mac OS 10.2.7 and 10.3 are not "true" 64-bit OSes, but the article does not clearly explain what a "true" 64-bit OS is. This had led to a lot of claims that the article is false or misinformed, rather than just unclear, which is certainly is.
32-bit Linux splits its 4GB of virtual address space per application into 3GB for the application and 1GB for the OS.
By default, yes, but you can change this with patches on the Net. For example, I can choose the splitting I want (well, 1, 2, 3 or 3.5GB) with Gentoo's custom kernel. However, I must admit that I never used that feature, so I don't know if it's safe or not, and I don't know if you can change the contiguous address space.