A version of RTKLIB optimized for dual band L1+L5 low cost GPS receivers, especially STA8100/STA9100 and BCM4775X. It is aligned with rtkexplorer (a modified version of rtklib 2.4.3) and will be reasonably closely synced to rtklib2.4.3 and rtkexplorer if possible). Documentation for RTKLIB is available at rtklib.com. This software is provided “AS IS” without any warranties of any kind so please be careful, especially if using it in any kind of real-time application.