Arduino IDE - Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware...
Reality Editor - MIT's new app lets you program any object
PlatformIO - Next-generation IDE for IoT
Arduino Eclipse plugin - Where Arduino meets Eclipse
My Devices - Drag and drop IoT project builder for Raspberry Pi
MINIBLOQ - miniBloq is an open source graphical programming environment for Multiplo™, Arduino™, physical computing devices and robots.