WinCompose¹, or more generally, use of a Compose key² to type all sorts of Unicode symbols or really any character (sequence) you like. People are used to thinking that they mostly can’t type what they don’t see on their keyboards, but a Compose key provides a universal method to type a large repertoire of characters through use of mnemonics.
I used to use the compose key lot, currently I really like Espanso.
It does arbitrary text replacement, has some pretty fancy features, but is also quite useful for turning \alpha or :laughing: into the symbols I want.
¹) http://wincompose.info/
²) https://en.wikipedia.org/wiki/Compose_key