Some professional coders are absolutely adamant that learning to program in assembly language in these ... and the standard linker, only a few X86_64 instructions are needed to create a tiny ...

[Shikaan] has an introductory article aimed to get you started at the “hello world” level of x86-64 assembly language. The second part is already up, too, and covers control structures.

Netwide Assembler (NASM) is an assembler and dissembler for the Intel x86 architecture and is commonly used to create 16-bit, 32-bit (IA-32), and 64-bit (x86-64) programs.