Keyboard layouts
Two macOS layouts, Idun British and Idun US. The normal keys stay as they are; Option and Option+Shift type the rune for the APL glyph that Dyalog's RIDE puts on that key.
To install, copy keyboard/Idun.bundle from the repository into
~/Library/Keyboard Layouts/, log out and in, then add the layout under
System Settings → Keyboard → Text Input.
The maps below print on A4. Grey is the APL glyph; black is the rune the key types.