2010-present (with Carsten Burstedde, Lucas C. Wilcox, Tobin Isaac, and James Martin), an MPI-based C-library that provides basic data structures and common facilities for parallel generic and scientific computing. libsc is released under the GNU LGPL version 2.1 (or later) and distributed with p4est.
2008-present (with Lucas C. Wilcox, Georg Stadler, Carsten Burstedde, Hari Sundar, Tobin Isaac, and James Martin), a high-order h-adaptive continuous and discontinuous finite element discretization library that is highly scalable.
2005-present, a subspace trust region interior reflective inexact Newton-CG solver for optimization problems with bound constraints. This code is written in Matlab, and a C version is implemented in libmaoi.