Wikipedia
Skypix is the name of a markup language used to encode graphic content such as changeable fonts, mouse-controlled actions, animations and sound to bulletin board system. The system was born on the Amiga in 1987 in the Skyline BBS package.
Scott Lee writes: "Skyline BBS, for the Amiga, was originally marketed under the name "Atredes BBS". It was written by someone named Michael Cox who lived in El Paso, TX in the mid/late 80s. He had contracted with a company, which I can't remember the name of, to market and sell the software and they did so under the name Atredes. Michael Cox eventually wound up selling the software himself and he renamed it Skyline. After about two years he grew tired of working on it and looked for a buyer. During that search, I did maintenance and housekeeping on the code for a few months before a user of the software that ran Omnilink BBS in Queens, NY bought the rights." "It was, BTW, cool software which allowed for plain text, ANSI graphics, as well as a proprietary graphical point and click "SkyPix" UI using special terminal software ("SkyTerm"). This was all around the '87 time frame which I think pegs it as the first graphical point & click BBS UI..."
Skypix was probably the world's first modern, fully interactive online graphics-and-sound protocol. Released as part of the Atredes BBS (later renamed Skyline) in 1987, Skypix for the first time allowed BBS sysops to run systems with graphics, fonts, mouse-controlled actions, animations and sound. It predated Mosaic - and thus the World Wide Web itself - by several years, though it had most of the same capabilities.
Technically a proprietary extension of ANSI codes, Skypix had a rich command set and featured the first "authoring program", Skypaint, which could generate Skypix files directly from a familiar-looking paint program. All a sysop had to do was insert these files in his system, and then people with Skypix-enabled terminal programs were presented with a rich, completely interactive graphics interface, as opposed to the ANSI graphics that were the state of the art until then.
Skypix might have remained a curiosity if creator Michael Cox hadn't thought to include a programming interface. Sysops who were conversant with the ARexx language (a variant of REXX for the Amiga) could write games and other programs using Skypix graphics and include them anywhere in their systems. This resulted in an enthusiastic group of Skypix hobbyists and many firsts, from the world's first fully graphical online chess games to the first online graphic adventure games, to the first online paint and photo galleries. These were widely traded and the average Skyline sysop had many of them on their systems. Other innovations included a type of animated graphic file that predated the invention of the animated GIF and worked on the same principle.
Skypix was available only on the Amiga computer, running on the program Skyline over the BBS and from BBS service side and a terminal called Skyterm from the side of the customer. A bit later Skypix support was implemented in one of the best terminal software of these years: JR-Comm, by Johnathan Radigan.
Amiga at that time was the only computer with sufficient graphics capabilities to make the project a reality. At one time over a thousand Skyline systems were operating the world over, thanks to the Amiga's international popularity. Amiga inventor Jay Miner himself ran a Skyline system for a time.