AMLET is software designed to estimate multinomial and mixed logit discrete choices models, which are increasingly popular in econometry. The software supports cross- sectional and panel data, and offers various optimization methods, including the new variable sample-size approach.
APBS is a software package for the numerical solution of the Poisson-Boltzmann equation (PBE), one of the most popular continuum models for describing electrostatic interactions between molecular solutes in salty, aqueous media. Continuum electrostatics plays an important role in several areas of biomolecular simulation, including simulation of diffusional processes to determine ligand-protein and protein-protein binding kinetics, implicit solvent molecular dynamics of biomolecules, solvation and binding energy calculations to determine ligand-protein and protein-protein equilibrium binding constants and aid in rational drug design, and biomolecular titration studies.
The ATLAS (Automatically Tuned Linear Algebra Software) project is an ongoing research effort focusing on applying empirical techniques in order to provide portable performance. It provides C and Fortran77 interfaces to a portably efficient BLAS implementation, as well as a few routines from LAPACK.
Apophenia is an open statistical library. It provides functions on the same level as those of the typical stats package (such as OLS, probit, or singular value decomposition) but doesn't tie the user to an ad hoc language or environment. The core functions are written in C, but a Python interface is included. It supports SQLite and MySQL databases, exponentially expanding the upper limit to manageable data sets. Since the library is significantly faster than most stats packages, computationally-intensive procedures like maximum likelihood estimation and Monte Carlo routines are easy to implement.
BuDDy was created as part of a PhD project on model checking of finite state machines by Jørn Lind-Nielsen. The package has evolved from a simple introduction to Binary Decision Diagrams (BDDs) to a full blown BDD package with all the standard BDD operations, reordering, a C++ interface, and a wealth of documentation.
Block Locally Optimal Preconditioned Eigenvalue Xolvers (BLOPEX) is a package, written in C and MATLAB, that includes an eigensolver implemented with the Locally Optimal Block Preconditioned Conjugate Gradient Method (LOBPCG). BLOPEX supports parallel MPI-based computations. BLOPEX is incorporated in the HYPRE package and is available as an external block to the PETSc package. Its main features are a matrix-free iterative method for computing several extreme eigenpairs of symmetric positive generalized eigenproblems; a user-defined symmetric positive preconditioner; robustness with respect to random initial approximations, variable preconditioners, and ill-conditioning (up to 10^16) of the stiffness matrix; and apparently optimal convergence speed.
Bear is a tool for calculating and testing discreteness of holonomy representations of complex projective structures on punctured tori. It can be used to draw pictures of Bers slices and explore the geometry of quasifuchsian space in the SL_2(C) representation variety. It also has powerful scripting features that make it easy to create complex animations or to automate larger calculations.