  Quantum electrodynamics and electroweak corrections are important ingredients
for many theoretical predictions at the LHC. This paper documents APFEL, a new
PDF evolution package that allows for the first time to perform DGLAP evolution
up to NNLO in QCD and to LO in QED, in the variable-flavor-number scheme and
with either pole or MSbar heavy quark masses. APFEL consistently accounts for
the QED corrections to the evolution of quark and gluon PDFs and for the
contribution from the photon PDF in the proton. The coupled QCD+QED equations
are solved in x-space by means of higher order interpolation, followed by
Runge-Kutta solution of the resulting discretized evolution equations. APFEL is
based on an innovative and flexible methodology for the sequential solution of
the QCD and QED evolution equations and their combination. In addition to PDF
evolution, APFEL provides a module that computes Deep-Inelastic Scattering
structure functions in the FONLL general-mass variable-flavor-number scheme up
to O($\alpha_s^2$). All the functionalities of APFEL can be accessed via a
Graphical User Interface, supplemented with a variety of plotting tools for
PDFs, parton luminosities and structure functions. Written in Fortran 77, APFEL
can also be used via the C/C++ and Python interfaces, and is publicly available
from the HepForge repository.
