All files associated with the LuaLaTeX package "selnolig".
The selnolig package suppresses typographic ligatures selectively, i.e., based on predefined search patterns. The search patterns focus on ligatures deemed inappropriate because they span morpheme boundaries. For example, the word shelfful, which is mentioned in the TeXbook as a word for which the ff ligature might be inappropriate, is automatically typeset as shelf{}ful, i.e., without the ff ligature.
For English and German language documents, the selnolig package provides extensive rules for the selective suppression of so-called "common" ligatures. These comprise the ff, fi, fl, ffi, and ffl ligatures as well as the ft and fft ligatures. Other f-ligatures, such as fb, fh, fj and fk, are suppressed globally; however, the package provides exceptions for names and words of non-English/German origin, such as fjord and Kafka.
For English language documents, the package further provides ligature suppression macros for a number of so-called "discretionary" or "rare" ligatures, such as ct, st, and sp.
The selnolig package requires use of the LuaLaTeX format provided by a recent TeX distribution such as TeXLive2013, TeXLive2012, or MiKTeX2.9.
To get started, you should (i) download the package's five .sty (style) files and the file selnolig.lua and (ii) install these files in a directory in a way that's appropriate for your TeX distribution. The package's user guide is in the file selnolig.pdf.
The files README.md (the file you're currently reading) and .gitignore are not part of the selnolig package and needn't be downloaded. The files with extension .tex and .fea need only be downloaded if you're interested in compiling the source code yourself.