I strongly suspect that a good GUI implementation will look like how file choosers on RISC OS work, and the command line environment might be inspired by both P

I strongly suspect that a good GUI implementation will look like how file choosers on RISC OS work, and the command line environment might be inspired by both Plan 9's namespaces and how data definitions (and their accompanying data control blocks) work in JES2 JCL on MVS. My only concern is that, without well-thought-out access controls, the only people who will care will be nerds or folks with a high frustration tolerance for poorly-considered human-computer interaction.