Here a few links to software I wrote:
A mature compiler for the Scheme programming language, targeting C, initially started by me but now actively developed and maintained by
a bunch of enthusiasts.
Another Scheme compiler, targeting x86_64 systems. Not actively developed anymore.
A minimalistic variant of the Acme editor, written in Tcl/Tk.
I use this for my daily work.
An implementation of the "Strand" parallel Prolog dialect, as described
in the book "Strand: New Concepts for Parallel Programming" by
Ian Foster and Stephen Taylor. Not actively developed and superseded by the
following project:
A compiler for FLENG, Flat Guarded Horn Clauses and Strand for x86-64,
Aarch64, ARM M1, armv7 and RISC-V systems.
A minimal variant of FLENG for CP/M, C64 and the "uxn" virtual machine.
A Forth system for the "uxn" virtual machine.