An open-source project called KryonOS is a GUI operating system for ESP32 microcontroller boards, built for use with a touch display and an SD card module. Built by a single developer who goes by Haris (GitHub handle Haris16-code) and released under the GPL-3.0 license, it adds a real touchscreen interface, a file explorer, and an app store to hardware that normally runs just one fixed program at a time.
The standout technical piece is its JavaScript runtime, built on the Duktape engine. Rather than requiring developers to write low-level C or C++ to build anything for the device, KryonOS exposes custom JavaScript bindings that give scripts working access to GPIO pins, touch input, the SD card filesystem, and connected sensors. According to the project's documentation, this runs inside a genuinely tight memory budget, with only around 90KB of free RAM typically left for the JS engine once the Wi-Fi stack and OS kernel take their share.
Because apps run through this JavaScript layer rather than being compiled directly into firmware, KryonOS supports installing and updating apps over Wi-Fi, without needing to reflash the device each time.
On the hardware side, the project uses separate SPI buses for the display and the SD card, a wiring choice meant to prevent the two from competing for bandwidth. It currently supports several ESP32 variants, including the WROOM-32, S2, S3, and C3, and its default pinout happens to match existing boards like the ESP32 Marauder, alongside dedicated support for devices such as the M5Stack Cardputer, the Cheap Yellow Display, and the LilyGO T-HMI.
