If you’ve spent any time perusing the RTKLIB source code you will surely be aware that it is very much what I would call “old-school” code. Comments are sparse and variable names tend to be short and not always very descriptive. The upside is that the code is quite compact, significant pieces of it can be seen on a single page which can sometimes be quite nice. The downside is it can be difficult to follow if you have not been poring over it for a long time. To help myself understand the code I have added a fair bit of commenting to most of the code used to calculate the carrier-phase solution, which is really the heart of the RTKLIB kinematic solution. This is mostly in the rtkpos.c file.
The changes are too extensive to spell out here so I have forked the RTKLIB code in Github and posted my commented code there. If you are interested, you can download it from the demo1 branch at https://github.com/rtklibexplorer/RTKLIB.
All the previous code changes are also there as well as a couple I have not yet posted about. The receiver data I have been using for these posts is also there in the rtklib/data/demo1 folder. The solution file updates for VS2010 c++ are in the rtklib/app/rnx2rtkp/msc folder and the modified executable is in the rtklib/bin folder.