Get the latest tech news
The RISC OS GUI
A look at the RISC OS 3.11 graphical interface from Acorn Computers Ltd in the United Kingdom, released in 1992 contemporary with Apple System 7. Please note that I am pretty new to this operating system so there may be inaccuracies and omissions in the text that follows.
You can type the desired number of rows or columns to add or remove, or wave the cursor over the underlying document window: the input box is filled for you. If you move the mouse cursor back onto the parent menu, the input submenu closes and the document window instantly regains focus, and with it, the yellow highlight. Only with Mac OS X did any mainstream graphical interface provide the smoothly rendered, fractionally spaced type that Acorn accomplished in 1992 or earlier.
Or read this on Hacker News