This is a "port" of ChaN's FatFs to the NavSpark platform and the modified Arduino IDE used for programming NavSparks. It requires the Adapter Board for the microSD card slot, or possibly any SD card slot wired identically (schematic is available on that store page).
This work was started by Jason Lin and/or others at SkyTraq. It was made available in the SD Card Library for Adapter Board forum post as a ZIP file. I moved all of the files (including the ones "embedded" in the example sketch) into a new library and moved that sketch into the examples directory. This allows it to be easily installed as a "library" in the Arduino IDE. I packaged this up as a ZIP file and made it available on the forum. That should be what's in the "forum-release" tag.
I then started seriously hacking on the code. I expanded on the wrapper classes in FatFileSystem.{h,cpp}, making separate File, FileInfo, and Directory classes. This actually simplified the code somewhat, which tried to do everything in one class. I added methods that wrapped more of FatFs's functions for working on files, etc.
I've also upgraded to FatFs 0.10b. For some reason the original release used version 0.07e, nearly five years old. Since I hadn't done the original adaption, it took some trial and error to get it working. But in the end I succeeded. The change isn't huge, but it does add some new features.
I've also added a "logger" example.