STOS BASIC is a dialect of the BASIC programming language for the Atari ST personal computer. It was designed for creating games, but the set of high-level graphics and sound commands it offers is suitable for developing multimedia software without knowledge of the internals of the Atari ST. STOS BASIC was developed by Jawx–François Lionet, and Constantin Sotiropoulos–and published by Mandarin Software (now known as Europress Software). History Although the first version of STOS to be released in the UK (version 2.3) was released in late 1988 by Mandarin Software, a version had been released earlier in France. Version 2.3 was bundled with three complete games (Orbit, Zoltar and Bullet Train), and many accessories and utilities (such as sprite and music editors). Initially implemented as a BASIC interpreter, a compiler was soon released that enabled the user to compile the STOS Basic program into an executable file that ran a lot faster because it was compiled rather than interpreted. In order to be compatible with the compiler, STOS needed to be upgraded to version 2.4 (which came with the compiler). STOS 2.4 also fixed a few bugs and had faster floating point mathematics code, but the floating point numbers had a smaller range. STOS 2.5 was released to make STOS run on Atari STEs with TOS 1.06 (1.6), and then STOS 2.6 was needed to make STOS run on Atari STEs with TOS 1.62. STOS 2.7 was a compiler-only upgrade that made programs with the STOS tracker extension (used to play MOD music) compile. There was a 3rd-party hack called STOS 2.07 designed to make STOS run on even more TOS versions, and behave on the Atari Falcon. Around 2001 François Lionet released via the Clickteam website the source code of STOS BASIC. On the 4th of April, 2019 François Lionet announced the release of AMOS2 on his website Amos2.tech. AMOS2 replaces STOS and AMOS together, using JavaScript as its code interpreter, making the new development system independent and generally deployed in internet browsers. AMOS2 is now known as AOZ Studio. Extensions It was possible to extend the functionality of STOS by adding extensions which added more commands to the language and increased the functionality. The first such extension to be released was STOS Maestro which added the ability to play sampled sounds. STOS Maestro plus was STOS Maestro bundled with a sound-sampler cartridge. Other extensions included TOME, STOS 3D,