"Why Create a New Unix Shell?": http://www.oilshell.org/blog/2018/01/28.html

If you want just one example, automatic completion in bash uses a bash parser written in bash, incompatible with the bash interpreter's own parser. OSH uses the same parser for both the interpreter and the completion engine. https://github.com/oilshell/oil/issues/208#issuecomment-4496...