Both the Windows Server 2003 x86 and the Windows XP amd64 kernel source code have been available for academic purposes. They are governed under the WRT License, which forbids re-distribution outside of the academic use. But yes, MS provided that source code with full documentation on how to build and debug each kernel.
I've built the WinXP kernel a few months ago just for nostalgic purposes, here's a VM running the custom kernel with a KDBG hook on NTQSysInfo [1]. The neat thing is that you can debug on the system itself, or via a serial port.
I also know that some people had success merging the /base/ code from the above licensed kernel (but the x86 version) and the leaked WinNT4 code. One even got so far as to manage a recompile of the NT setup, building a custom NT OS from scratch. Though that's violating the WRK and NT license left and right.
You're talking about cool things, no doubt about it, but code made available for academic purposes only is still not open source.
This isn't just pedantry, we are scientists from different countries, with many of us having learned English as a second or third language (I'm from Romania, hi), so it's better to be precise in language.
And in this instance "open source" is a good term to be precise about, because the OSI definition specifies exactly what you can and cannot do with it. And in particular (1) you can use it for any purpose, even for evil ones and (2) you can fork it and modify it in any way you wish.
So when I hear "open source", I don't have to go and read the license and validate that these requirements are true, because OSI has already done that for me and they have lawyers that know how to read licenses. This saves me time, headaches and money.
And academic, non-commercial licenses do not qualify. Microsoft itself has introduced an alternative term for such academic, non-commercial licenses and I think it's a good one: Shared Source. Lets use it.
> So when I hear "open source", I don't have to go and read the license and validate that these requirements are true...... This saves me time, headaches and money.
Most of us have some vague understanding about Licenses.
Eg: MIT/X11 specifically says "...FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT..." but it is "open source"
That is, if you earn too much money from some MIT License software, the author itself is free to sue you the way he/she can (eg, patents). One example could be dotNet from M$.
So better stick to software pieces that are licensed under GNU [A]GPLv3 or Apache v2 (If you care patent issues). Also, note that you can trust "free software" guys more than "open source" ones.
edit: Also note that this can also be a reason why Apple didn't update any GNU packages once they were relicensed to GPLv3+. (The main reason could be the GPLv3 requirement that the user should be able to replace the software if [s]he wish to. Apache doesn't have this requirement, and Apple used that for swift)
> the author itself is free to sue you the way he/she can (eg, patents). One example could be dotNet from M$.
That's not actually true. In law, at least in the US, there's such a thing called Estompel [1], and licenses like BSD / MIT do have an implicit patents grant [2], unless the software is also accompanied by an explicit patents license (like Microsoft is doing), in which case that license takes precedence.
Of course, you can't be totally safe with an implicit patents grant, because its applicability depends on jurisdiction, plus it's always unclear if you can also count on it for derived works, etc. But then again, this is why GPL v2 is still safe. Remember that the Linux kernel is licensed under GPL v2? So what, are we all screwed?
> note that you can trust "free software" guys more than "open source" ones.
With all due respect, but many "free software" guys tend to be zealots and I can't take them seriously anymore. Not when the FSF starts doing stupid shit, like preventing Emacs on MacOS from supporting emoji just because the "free operating systems" would be at a disadvantage. Talk about crazy.
Also, in my opinion AGPL does not pass the OSI definition and it was probably accepted only because it would have brought out the crazy, but that's a personal opinion.
The complete disregard for any legalities has certainly resulted in some very interesting and even useful software. It reminds me of the (largely Asian) community that formed around modding/hacking/cracking Windows in various ways, and the products that resulted: CDs and DVDs with a dozen different versions of Windows on them, liveCD/USB/DVDs, and chimeric combinations of OSes. If I remember correctly, Vista and later had significantly increased the number of integrity checks in the OS, arguably for security reasons, which made this sort of experimentation more difficult; but in the 2K/XP/2K3 days, it was pretty open.
Those in the scene may recognise the names Roy and Wengier, 911cd, and the China DOS Union.
I've built the WinXP kernel a few months ago just for nostalgic purposes, here's a VM running the custom kernel with a KDBG hook on NTQSysInfo [1]. The neat thing is that you can debug on the system itself, or via a serial port.
I also know that some people had success merging the /base/ code from the above licensed kernel (but the x86 version) and the leaked WinNT4 code. One even got so far as to manage a recompile of the NT setup, building a custom NT OS from scratch. Though that's violating the WRK and NT license left and right.
[1] http://i.imgur.com/BeiME5X.png