Is it true that Linux Kernel components MUST be open source? If so, is there "an official" link for this statement?

The reason I am asking is related to Blu-Ray playback on Linux. Curious as to why commercial Blu-Ray player apps don't hide their AACS keys within obfuscate player binary - and publish commercial Linux versions of their player.

When an app installs, it can install stuff in user and kernel space right? Or is the notion of "kernel mode" in Linux different from that of Windows?

Thx.

The linux kernel is open source by default, but kernel modules like NVidia are not. When the linux kernel detects proprietary modules on boot, it prints a little message: <module-name> module taints kernel! The whole concept of open source allows you to use it however you wish. Some distributions will not allow proprietary software in their repositories, however. The general slant in the linux world is to shy away from commercial software. Nero is a good example. They have some linux software, but I don't know anybody that uses it. We would rather work a little harder and learn something new than pad the big boys' pockets. I do use the proprietary NVidia driver, but I bought the NVidia equipment and the driver is free. I see no problem with that.

Joerg Shilling built blu ray support into his software. See below.

http://cdrecord.berlios.de/private/cdrecord.html

Furthermore, companies consistently find that there are market advantages, inherent in open-source / collaborative software development strategies, which outweigh any notions of "keeping it secret."

Is it really so gosh-darned secret what the switches and knobs of your hardware video-card actually do? Extraordinarily unlikely... "Nothing secret here. These aren't the 'droids you're looking for. Move along."

IMHO, we would not have any of the electronics goodies that we now have ... nor would we have the software we are using right now (on the host side and perhaps on your client side) ... if it were not for open-source, collaborative development. Frankly, we could not afford to have done it, and no one would have been able to cooperate to the degree that was required. To me, it is unfortunate that the word "F(ree)" appears continuously in the context of Open-Source Software, because software is anything but "free."

As an aside, I am constantly confronted by the lack of quality of Android applications that are not supported by some clear revenue model and/or that are the work of one person vs. a community. (Most especially so when the word is, "and.") No one works for free. Not for long. As Alice Cooper put it, "Nothing's Free..."

disappinting. you should know better. it is not about free as in no money, it is about free as in freedom!!!!