I invented a programming language where you use Unicode box-drawing characters to draw a structure of boxes and lines:

                    ╓───╖
                    ║ ! ║
                    ╙─┬─╜   ┌───╖  ╔═══╗
                ┌─────┴─────┤ > ╟──╢ 2 ║
                │           ╘═╤═╝  ╚═══╝
  ╔════╗  ┌───╖ │             │
  ║ −1 ╟──┤ + ╟─┴─┐           │
  ╚════╝  ╘═╤═╝   │           │
          ┌─┴─╖   │    ╔═══╗  │
          │ ! ║   │    ║ 1 ║  │
          ╘═╤═╝   │    ╚═╤═╝  │
            │   ┌─┴─╖  ┌─┴─╖  │
            │   │ × ╟──┤ ? ╟──┘
            │   ╘═╤═╝  ╘═╤═╝
            └─────┘      │

The language is called Funciton (pronounced: /ˈfʌŋkɪtɒn/) and the above example demonstrates the factorial function.

YouTube playlist: https://youtube.com/playlist?list=PLkG32PHxWoJaetjKUMVRONWLg...

Language specification: https://esolangs.org/wiki/Funciton

Interpreter: https://codeberg.org/Timwi/Funciton