SmileBASIC/Petit Computer is the coolest series I've ever seen on a series of consoles and I've NEVER seen anyone talk about it and it's so sad.
It's a fucking BASIC interpreter that people can make games and programs in. It started on the DSi in 2011 and it's been on every Nintendo console since (mostly. The Wii U version was Japan only).
People have made some really really cool stuff in it. There's some really impressive games in it considering how limiting the BASIC environment can be. The original celeste has been ported. There's a fucking gameboy emulator on SmileBASIC4 for the Switch.
There's a gameboy emulator on a nintendo console that can load any rom you want without custom firmware.
Someone wrote a whole ass modem program that you could to transfer files from a PC to the 3DS version of it and then made an Arduino interface for transferring files to the Switch version.
It's so sad how small the community for this series is because it's so fun to try and write games and programs and play what others have made.