A list of the 4 libraries in the architecture nrf5.

arduino-NVM Direct flash memory access, round robin virtual pages and EEPROM like memory. (Flash, VirtualPage, NVRAM)
iBit_Arduino A control library for iBit Board.
MicroGamer A library for content creation on the Micro:Gamer gaming platform
NRF51_Radio_library Microbit Radio library for NRF51, based on runtine inplementation from Landcaster University