I would like to propose a new hardware development kit Modulowo Explore E for Intel Edison. Board enables easy extension of compute module with additional modules, such as sensors, touch switches, motor controllers and LED drivers, communication modules, GPS and much more. DevKit includes a connector for Intel Edison platform, two Modulowo duoNECT connectors for add-ons modules, GPIO, SPI, UART and I2C interfaces connectors, two micro USB (USB OTG and USB/UART converter), 12-bit Analog-to-digital converter (optional 16-bit) for measuring analog signals, voltage logic level translators (tolerates +3,3V/+5V signals), battery charger (only for Intel Edison) and connector for additional power supply for expansion modules.
Technical details http://tech.modulowo.com/76 and modulowo.com/intel-edison
Add-on Board Example
Expansion modules can also be connected to the Raspberry Pi