TomOS 3

TomOS 3 is a graphical operating system developed and released by Talking Software. It was released in 1977. When the TomOS 3, along with TomOS 4 and TomOS 5 are unsupported by Talking Software in 1996, TomOS 3 was supported for 19 years by the time of the discontinuation, making it the longest-supporting operating system in Talking Software computer industry.