Linus Torvalds is the creator of the Linux kernel. His preferred programming language is C. Linus started out programming in what he assumed to be "assembler" when he was really just hard-coding binaries with 0's and 1's. This may be why he is very good at micro-optimizations when coding in C.
Creator of the Linux Kernel
Torvalds created the Linux kernel because wanted something Unix-like which he could use on a regular computer. He fell in love with regular Unix at the University and wanted something similar on his home computer. There was nothing like that available at the time so he wrote his own Unix-clone.
Torvalds wrote this in the "Notes for linux release 0.01" when he first released his kernel to the public in 1991:
"This is a free minix-like kernel for i386(+) based AT-machines. Full source is included, and this source has been used to produce a running kernel on two different machines. Currently there are no kernelbinaries for public viewing, as they have to be recompiled for different machines. You need to compile it with gcc (I use 1.40, don't know if 1.37.1 will handle all __asm__-directives), after having changed the relevant configuration file(s). "
Other Notable Projects
Torvalds is the author of the very popular git version control software which has been adopted by most free software project as well as many commercial projects. The largest source code repository as of 2019 is Microsoft GitHub. It is, as the name implies, based on the git software.
View on C++
Torvalds had this to say about C++ in an e-mail exchange in 2007:
"C++ is a horrible language. It's made more horrible by the fact that a lot of substandard programmers use it, to the point where it's much much easier to generate total and utter crap with it. Quite frankly, even if the choice of C were to do *nothing* but keep the C++ programmers out, that in itself would be a huge reason to use C."
Kernel development model
The Linux kernel is known to be very stable. This is in a large part due to Linus policy of "We do NOT break user-space". If a kernel change breaks a user-space program then it is, in his view, a kernel bug - regardless even if it's because a user-space program relies on some quirk in the kernel.
Ability to say no
There are many examples of the importance of saying no to code which would be bad for the kernel.
David Howells submitted a patch which would allow a secure kernel to add keys willy nilly in 2013.
Can you pull this patchset please?
It provides a facility by which keys can be added dynamically to a kernel that is running in secure-boot mode. To permit a key to be loaded under such a condition, we require that the new key be signed by a key that we already have (and trust) - where keys that we "already have" could include those embedded in the kernel, those in the UEFI database and those in cryptographic hardware.
Now, "keyctl add" will already handle X.509 certificates that are so signed, but Microsoft's signing service will only sign runnable EFI PE binaries.
We could require that the user reboot into the BIOS, add the key, and then switch back, but under some circumstances we want to be able to do this whilst the kernel is running."
Torvalds had this to say about said patch-set:
"Not without a lot more discussion first.
Quite frankly, this is f*cking moronic. The whole thing seems to be designed around stupid interfaces, for completely moronic reasons. Why should we do this?
I already dislike our existing X.509 parser. And this makes the idiotic complicated interfaces, and now it goes up to 11."
Torvalds has known to be a bit harsh when he has had to explain kernel development fundamentals to incompetent people. This resulted in him being sent to a re-education camp and the introduction of a CoC with Linux Kernel 4.19. Many feared that this would hamper his ability to clearly say no to buggy code and foolish design decisions. These fears were unfounded and Linus remains very based.
Torvalds lives in the US. Further information about his personal life is not required or desired as it has little to no relevance on his management of the Linux kernel.
Linux Torvalds does not have anything which resembles a personal website or a blog. What he does have is linux.git at git.kernel.org.