The Linux kernel is named for its creator, Linus Torvalds. The practice of appending an X was for Unix and Unix-like systems.
date -u +%A
There is no "full form".
useradd <username> -c "Full name" passwd <username> userdel <username>
All versions of the Linux kernel are "full featured." The latest stable version of the Linux kernel as of May 17, 2011 is 2.6.38.6.
No direct abbreviation for lawyer. "Atty." is an abbreviation for "attorney."esq
The current Linux kernel version is 3.9.
Linux is the kernel.
Linux Trace Toolkit
OpenOffice and LibreOffice are both full office suites used in Linux distributions.
The kernel.
It's name begin with a full stop, like .profile or .bash_history(ls .* or ls -a shows it nevertheless)
There are no "joined" Linux and Windows operating systems, so there is no name for them.