To me, a few things that stands out, that I'm increasingly looking to emulate, that are mostly not about the low level API/ABI: * Assigns. Basically aliases fo

To me, a few things that stands out, that I'm increasingly looking to emulate, that are mostly not about the low level API/ABI: * Assigns. Basically aliases for paths, but ephemeral and can be joined together. E.g. the search path for executables is the assign C:. The search path for dynamic libraries ins libs:. I've added basic, superficial support for assigns to my shell. It's a hack, but being able to just randomly add mnemonics for projects is nice, and not having to put them in the filesystem as a symlink somehow also feels nicer even if it only saves a few characters. * Datatypes. AmigaOS apps can open modern formats even if the app hasn't been updated for 30 years as long as they use datatypes: Just drop a library and descriptor file into the system. * Screens. I'm increasingly realising I want my wm to let apps open their own virtual desktops, and close them again, as a nice way of grouping windows without having to manually manage it, and might add that - it'd be fairly easy, and on systems that don't support it the atoms added would just be a no-op. The dragging was nice to show off at the time, but less important. Ironically, given the Amiga was one of a few systems offering overlapping windows when it launched, screens often served as a way for apps themselves to tile their workspaces on a separate screen/desktop, and my own wm setup increasingly feels Amiga-ish - I have a single desktop with floating windows and a file manager, just like the Amiga Workbench screen, and a bunch of virtual desktops with tiling windows. In terms of the API, one of the things I loved was more something that evolved: The use of "dispatch/forwarding" libraries, like e.g. XPK, that would provide a uniform API to do something (like compression) and an API for people implement plugins. So much of the capabilities of Amiga apps are down to the culture of doing that, and which Datatypes was an evolution of, that means the capabilities of old applications keeps evolving.