I would like to start that discussion about the Open Source software RTK-LIB that allows anyone to post-process GNSS observations (RINEX) for free and also to perform RTK (RTCM).
It seems UAV hobbyists and robots makers are more familiar than surveyors with the RTK-LIB. That library has been developed by Mr TAKAZU from Japan.
RTKLIB is an open source program package for standard and precise positioning with GNSS (global navigation satellite system). RTKLIB consists of a portable program library and several APs (application programs) utilizing the library.
I would very much appreciate your feedbacks on that topic and on what GNSS post-processing software you are working with ? It seems post-processing a bit of fashion nowadays but RTK-LIB can also carry on your observations in RTK mode and even using PPP.