hyx, a minimalistic (< 2300 lines of C) but powerful (hex/ASCII, insert/replace/delete, copy/paste, undo/redo, search, colors, vim-inspired controls) Linux terminal hex editor (current version 2021.06.09)
ynetd, a small (< 400 lines of C) server for binding programs to TCP ports (current version 0.1.2, 24 May 2017)