There is the 010 Editor, at heart a cross-platform scriptable hex editor with a template language [1]. It has a central template repository [2] as well as templates around the internet (e.g. 3, 4).

But it being a paid tool means there are fewer template contributions from 13 year olds, which if we are all honest make up the majority of unpaid open source contributions - they simply have more spare time.

1: https://www.sweetscape.com/010editor/

2: https://www.sweetscape.com/010editor/repository/templates/

3: https://github.com/tge-was-taken/010-Editor-Templates/tree/m...

4: https://wiki.redmodding.org/cyberpunk-2077-modding/modding-k...