This is a bunch of useful C modules. The name of this kind-of-library, "LIFT", can be interpreted as a recursive acronym: Lift Is not a Framework or a Toolkit (a bunch of useful C modules).
Also, it is a slight pun on a well-known C++ library. This is C, we don't need a boost we just need a lift. :)
Well, there is the "master" include file lift.h, but, in most
cases, you should just include the header of the module that
you need.
The documentation should be visible here Doxygen generated documentation.