Level 1, Level 2, and Level 3 packages can be built independently of the applications and used in your own codes if you wish. However, please heed this warning:
Given the number of modules and the combinatorically larger variety of possible ways to combine them, we suggest that if you are new to this game you can save yourself a lot of frustration by checking out one of the application suites above.

Having said all that, the currently available Level 3 SciDAC modules are described and listed below:

QUDA	Maintainer: Mike Clark (mclark[at]nvidia[dot]com) Source code:  tar-ball   repository Web site:  http://lattice.github.io/quda Reference to cite:  Comput.Phys.Commun. 181 (2010) 1517, Proceedings of SC 2011
Level 1	optional: QMP
requires	CUDA

QUDA is a library for performing calculations in lattice QCD on graphics processing units (GPUs), leveraging NVIDIA's CUDA platform. The current release includes optimized Dirac operators and solvers for the following fermion actions: Wilson, Clover-improved Wilson, Twisted mass (degenerate or non-degenerate), Improved staggered (asqtad or HISQ), Domain wall.
  Implementations of CG, multi-shift CG, BiCGstab, and DD-preconditioned GCR are provided, including robust mixed-precision variants supporting combinations of double, single, and half (16-bit "block floating point") precision. The library also includes routines for HISQ link fattening and force terms for the HISQ fermion action and one-loop improved Symanzik gauge action. Use of many GPUs in parallel is supported throughout, with communication handled by QMP or MPI.

QOPQDP	Maintainer: James Osborn (osborn[at]alcf[dot]anl[dot]gov) Source code:  tar-ball   repository Web site:  http://usqcd-software.github.io/qopqdp Reference to cite:
Level 2	QDP and QIO
Level 1	QMP and QLA

QOPQDP is an implementation of the QOP level-three interface using QDP. It contains various inverters and force terms that can be used across many platforms and still achieves high performance.

MDWF	Maintainer: Andrew Pochinsky (avp[at]mit[dot]edu) Source code:  tar-ball   repository Web site:  https://usqcd.lns.mit.edu/redmine/projects/mdwf Reference to cite:
Level 2	QDP and QIO
Level 1	QMP and QLA

MDWF is a Level 3 inverter package, for performing inversions of a variety of Domain Wall Kernels, including Shamir, Moebius and Borici variants.

Clover	Maintainer: Andrew Pochinsky (avp[at]mit[dot]edu) Source code:  tar-ball   repository Web site::  https://usqcd.lns.mit.edu/redmine/projects/clover Reference to cite:
Level 2	QDP and QIO
Level 1	QMP and QLA

Clover is a Level 3 solver for Clover fermions from MIT.

CG-DWF	Author: Andrew Pochinsky -- no longer maintained Source code:  tar-ball    Web site:  http://www.mit.edu/~avp/sse/ Reference to cite:
Level 2	QDP and QIO
Level 1	QMP and QLA

CG-DWF This module provides a Domain-Wall inverter optimized for SSE, BlueGene and AltiVec architectures.