We covered Real Time Logic's open-source lightweight Minnow Server for microcontrollers last year, and now the company has released another project: Barracuda App Server for ESP32.
This project is more complex and requires an ESP32 board with PSRAM to run such as boards based on ESP32-WROVER module with 4 to 8MB PSRAM. The Barracuda App server (BAS) comes with a Lua VM, and in complement with the LSP App Manager that facilitates active development on the ESP32 by providing a web interface.
The Barracuda App Server runs on top of FreeRTOS real-time operating system part of Espressif free ESP-IDF