Linux is a free to download operating system, so it is difficult to put a specific value on it.
no
Yes, very much. Linux is a developing and cutting edge OS.
pretty much anything that can run Linux and sendmail
quicker answer is which linux distro does not work? Pretty much all will work
The first OS was technically LEO I (1951) MS DOS (1981) Linux (1991 Even though MS came out first Linux is based on the much much older Unix based system which came out in 1969.
A Mac is a computer the cost of which varies depending on which model you buy. Linux is an operating system that is free. You can use the Linux operating system on a Mac if required.
Yes, Linux is like an operating system much like Windows OS or Mac OS. Linux is kind of like a community of Operating Systems. A popular OS from Linux is Ubuntu.
Nobody. Code is contributed by and remains the property of the many volunteers and employees of various companies.
I'm assuming you are referring the Linux operating system. Linux is 100% free. If you pay a penny for it, get your money back. There are hundreds of different distributions of Linux. Some of the best beginner distro's are Ubuntu and Linux Mint. Check the related links below.
No, Linux has .so (Shared object) and .ko (Driver) files. Shared objects work in much the same way as dynamically linked libraries, except in a much better way that doesn't screw things up. There is no real Linux "DLL hell" equivalent.
U-Boot is not actually part of Linux; it is a separate project. It is a bootloader, much like GRUB, often used in embedded devices.
As much as you can give it. Architecturally, Linux can support 64 GB on an x86 server, and a theoretical 16 exabytes on an x86-64 (no current server can come close to supporting that much RAM in hardware).