This tutorial focuses only on the x86 architecture families.
Here are some other popular architectures which you should have in mind as well:
https://en.wikipedia.org/wiki/PowerPC
Created by IBM, Motorola and Apple.
But IBM and Motorola are dying, Apple moved to Intel in 2005 for power efficiency, Xbox One and PlayStation 4 moved to x86-64 in 2013.
Used on Nintendo GameCube (2001) up to Wii U (2012), PlayStation 3 and Xbox 360.
http://en.wikipedia.org/wiki/MIPS_instruction_set
RISC. Was really hot in 80s, bought by SGI. More recently bought by Imagination Technologies https://en.wikipedia.org/wiki/Imagination_Technologies.
Used mostly on embedded systems, and notably video game consoles: Nintendo 64, Sony PlayStation, PlayStation 2.
Officially supported on Android.
http://www.androidauthority.com/nintendo-64-android-l-microcontrollers-story-mips-538596/
Lextra story: http://probell.com/lexra/ It is not possible to patent an entire ISA as there is too much prior art, but companies patent instead specific novel instructions, and the compatibility break kills off reimplementors.
https://en.wikipedia.org/wiki/SPARC
Created by Sun for its operating system Solaris. Now owned and used by Oracle. Not used much by anyone else.
Was meant to be the ultimate RISC beats Intel and Windows coalition, but it failed.