This is an addon module for the Raspberry Pi. Intended for use with the lowpan userspace tools, it adds support for 6LoWPAN over 802.15.4 (2.4GHz) to a Raspberry Pi running Linux.
The module comprises a chip antenna, crystal oscillator, and an Atmel AT86RF233, which is a 2.4GHz SPI-to-antenna transceiver IC with 802.15.4 hardware assist. This is therefore an SPI-to-airwaves 802.15.4 solution.
The header pins are matched to pins 15-26 of the RPi P1 header, but this design is otherwise not RPi-specific. It would not be wrong to call this a simple AT86RF233 breakout board with an antenna and crystal.