Actual assembly in mainstream use:
x86
arm
risc v

mainstream byte code:
jvm
.net (I think)
wasm

fake assembly people may write:
llvm
wasm

wat (web assembly text) is actually written is S-expressions, like lisp but without code as data.

Edit: formatting

I'm making my own, because all mainstream options are bloated for my usecase...

How many do you want?