Picotron
From the website:
Picotron is a Fantasy Workstation: a self-contained creative environment built for imaginary hardware. Create cute Lua apps that can be run inside Picotron as windowed userland processes, shared as cartridge files, or exported to stand-alone HTML apps.
As someone who missed out on the days of the computers being things you had to program yourself to do useful things, experiments like the Picotron strike a retro-nostalgic chord in my heart: a longing for a technology and time that I never actually got to experience. It helps that the system is beautiful and looks fun to work with. The author also has a couple of similar projects: (Pico-8 and Voxatron)
All of the above are for-pay, think of it as an investment in good, beautiful things you want to see in the world.