I've been working on a simple OS for tinkering and running bare metal apps on vintage PCs.
Since I couldn't quite decide whether to target pure 16-bit, or slightly more capable 32-bit machines, I ended up with two separate versions.
GentleOS/16 is confirmed to work on 80186+. It requires less than 192KB of RAM and a monochrome CGA display with 320x200 resolution.
GentleOS/32 works on i386+, requires 4MB RAM, supports VGA in 640x480x16 mode or any 256-color VESA mode.
By design they're both entirely monolithic (single binary, single thread) and only support standard PC devices (CGA/VGA, 8042 keyboard, PS2 mouse, serial mouse, PC speaker, etc). The only plans for the future are bugfixes, optimizations, adding more apps, and testing on different hardware.
Below are a few photos/screenshots, you can find more on GitHub.
Cheers!



