sbase and ubase from https://core.suckless.org https://core.suckless.org maybe? In a wider context maybe Plan 9 from user-space https://9fans.github.io/plan9po

sbase and ubase from https://core.suckless.org https://core.suckless.org maybe? In a wider context maybe Plan 9 from user-space https://9fans.github.io/plan9port https://9fans.github.io/plan9port In an even wider context the stuff https://chimera-linux.org https://chimera-linux.org does. Also https://landley.net/toybox/status.html https://landley.net/toybox/status.html