Arduino IDE - Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware...
My Devices - Drag and drop IoT project builder for Raspberry Pi
PlatformIO - Next-generation IDE for IoT
ioBroker - flexible and modular application for the IoT and Smarthome
Visuino - Visuino is a visual programming environment that lets you write programs from Arduino circuit boards.
Nim Home Assistant (NimHA) - Nim Home Assistant is an open-source home automation platform running on Nim.