The RISC OS, specifically the "Arthur" version released in 1987, was the first to have something like the Dock. Look at the screenshot on the Wikipedia page.

The RISC OS, specifically the "Arthur" version released in 1987, was the first to have something like the Dock. Look at the screenshot on the Wikipedia page. https://en.wikipedia.org/wiki/History_of_RISC_OS https://en.wikipedia.org/wiki/History_of_RISC_OS