  The MFEM (Modular Finite Element Methods) library is a high-performance C++
library for finite element discretizations. MFEM supports numerous types of
finite element methods and is the discretization engine powering many
computational physics and engineering applications across a number of domains.
This paper describes some of the recent research and development in MFEM,
focusing on performance portability across leadership-class supercomputing
facilities, including exascale supercomputers, as well as new capabilities and
functionality, enabling a wider range of applications. Much of this work was
undertaken as part of the Department of Energy's Exascale Computing Project
(ECP) in collaboration with the Center for Efficient Exascale Discretizations
(CEED).
