EstyJS is an emulator for the Atari ST, written in 100% pure JavaScript, originally developed by Darren Coles. Since 2024 and the release of EstyJS 2.0, the project is maintained by Kai Eckert. The source code is available on GitHub.
ProSystem Alternatives
ProSystem is described as 'The ProSystem Emulator is an Atari 7800 emulator for the PC and Windows OS. The emulator was written in C++ using the Windows API and DirectX. It emulates the Atari 7800 NTSC and PAL TV standards' and is a Game Emulator in the gaming software category. There are more than 10 alternatives to ProSystem for a variety of platforms, including Windows, Linux, Mac, Android and Web-based apps. The best ProSystem alternative is Mame, which is both free and Open Source. Other great apps like ProSystem are MAME4droid, Stella, Z26 and EMU7800.