xFitter  is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton for many different kinds of analyses in Quantum Chromodynamics (QCD). It incorporates experimental data from a wide range of experiments including fixed-target, Tevatron, HERA, and LHC. xFitter version 2.0.0 has recently been released, and offers an expanded set of tools and options. The new xFitter 2.0.0 program links to the APFEL code  which has implemented generalized matching conditions that enable the switch from NF to NF +1 active flavors at an arbitrary matching scale μm. This enables us to generalize the transition between a FFNS and a VFNS and essentially vary continuously between the two schemes; in this sense the matching scale μm allows us to unify the FFNS and VFNS in a common framework . This paper provides a brief overview of xFitter with emphasis of these new features.