Snowdrop OS v4 (operating system from scratch in assembly language)
Snowdrop OS is my homebrew operating system.
It is very simple, and is programmed from scratch, using only assembly language (for the x86 processors). It has a custom PS/2 mouse driver and supports basic multi-tasking.
It comes with a Tetris clone, also written in assembly language.
Also includes a file manager and a text editor.