Windows emulation vs. JavaVM: Sal, I hate to keep coming back to this, and this is my last word, I promise. People have tried windows emulation, just as they used to try DOS emulation, with limited success. Windows is this vast ever-changing, ever-growing blob, and there's no catching up. I'd love to see Microsoft build a Windows VM that would allow Windows applications to run elsewhere. But get real.
Winframe is not a Windows VM; it just displays windows for apps running on the winframe server on remote machines. And it's not a windows clone. The server is Windows/NT + extensions. DEC has had some success emulating x86 machine ops under Alpha, with sophisticated dynamic translation mechanisms. They claim the fastest Alpha's are faster than the fastest PPro's running under this mechanism. But they don't try to emulate Windows; this is under a native port of NT. OS/2 has windows capability, but it started with some cooperation from MSFT, and I don't think its windows compatibility is up to date. Sun tried hard with WABI, but again, I don't think they've been able to keep up. There's a GNU offshoot called wine, for WINdows Emulator; it runs on top of unix/X windows and can run a few apps, for a while. Of course, microsoft has no interest in aiding WABI,WINE,or OS/2; Winframe and the Alpha/NT port are under its control.
Windows is a moving target. JVM is compact and well-specified, and Sun is not trying to kill off software emulation of JVM. The Window API is 3000-plus function calls plus whatever new API Microsoft decides to throw in next week. Unlike x86, it is largely clone-proof by complexity and plasticity; you have to feel your way through the semantics. There's no doubt some underlying logic somewhere in its design that might make duplicating its functionality possible, but that's not public information. Figuring out what all the 3000-odd calls are supposed to do, and how they all interact, is nothing at all like porting the JavaVM. I know you'll persist in saying there's no difference, but I think most anyone who knows any technical details of Windows and JavaVM would agree with me that JavaVM is about a thousand times more portable or clonable that the Windows API.
Cheers, Dan. |
