Explore M3 is a feature rich ARM Cortex M3 development board. It can help you prototype ideas faster with Arduino and take them beyond, with bare metal programming, RTOS support and lower power modes if need be. All the source-code and hardware design files are open-source including the on board boot-loader. This makes it easy in using the board/chip in your custom designs
We are currently crowdfunding the board, click on the link below to support. https://www.crowdsupply.com/explore-embedded/explore-m3