I am making a Flow Based Programming system for the shell,
http://sam.nipl.net/code/net2sh. It is a self-hosted translator.
There is also a tool to draw graphs from the programs, like these:
I also ported Ken Thompon’s shell from UNIX 6th edition in 30 minutes:
This has been done already at http://v6shell.org, and I’m sure they did a better job, but there was this long copyright notice…
I’m not planning to use Ken’s shell with net2sh, but it is a precious piece of UNIX history which deserves to be studied and remembered.