The RISC OS GUI

> When a program needs to allow the user to choose a file, drag and drop is again used, with the window providing a drop area to collect the file

The neat part was you could "save" from one app into another, without having decided to actually save the file yourself yet at all.

I have to echo the comments about the mouse button "Adjust". Being able to move windows about while they preserve depth position without some obscure shortcut was very useful.

Over the years I've grown to appreciate the extent to which whatever vision there may have been behind RISC OS originally the lack of a proper GUI toolkit and serious OS internals held them back such that by Win95 Windows really was better. At exhibitions in 94/95 Acorn devs themselves were conspicuously more interested in running NetBSD than RISC OS, and it always seemed a shame they didn't make a more serious effort to get some descendant of the RISC OS desktop ported over to a UNIX like kernel, rather like a more serious shot at the ROX desktop, but in truth Win95 won the late 90s desktop paradigm war convincingly.

I searched for "ARM" and didn't see it in the article. The Acorn ran on ARM (that's what the A in ARM stood for anyway, Acorn RISC Machine)

You can run RISC OS on a Raspberry Pi which is also ARM based.

https://www.riscosopen.org/content/sales/risc-os-pi

I do like the "Adjust" mouse button.

EDIT: especially that you can use it to do multiple menu selections without actually closing the menu.

See also:

• <http://toastytech.com/guis/indexriscos.html>

• <https://guidebookgallery.org/guis/riscos>