Search for "rc shell" and "es shell" https://en.wikipedia.org/wiki/Rc_(Unix_shell) https://en.wikipedia.org/wiki/Rc_(Unix_shell) https://wryun.github.io/es-sh

Search for "rc shell" and "es shell" https://en.wikipedia.org/wiki/Rc_(Unix_shell) https://en.wikipedia.org/wiki/Rc_(Unix_shell) https://wryun.github.io/es-shell/ https://wryun.github.io/es-shell/ They are alternative shells, both from the 90's I believe. POSIX was good in some ways, but bad in that it froze a defective shell design It has been acknowledged as defective for >30 years https://www.oilshell.org/blog/2019/01/18.html#slogans-to-explain-the-project https://www.oilshell.org/blog/2019/01/18.html#slogans-to-exp... --- es shell is heavily influenced by Lisp. And actually I just wrote a comment that said my project YSH has garbage collection, but the es shell paper has a nice section on garbage collection (which is required for Lisp-y data structures) And I took some influence from it Trivia: one of the authors of es shell, Paul Haahr, went on to be a key engineer in the creation of Google