LHAPDF provides a unified and easy to use interface to modern PDF
sets. It is designed to work not only with individual PDF sets but
also with the more recent multiple "error" sets. It can be viewed as
the successor to PDFLIB, incorporating many of the older sets found in
the latter, including pion and photon PDFs. In LHAPDF the computer
code and input parameters/grids are separated thus allowing more easy
updating and no limit to the expansion possibilities.
