f2py is a command line tool for binding Python and Fortran code. It scans Fortran 77/90/95 code and generates a Python C/API module that makes it possible to call Fortran routines and to access Fortran data (COMMON blocks and Module data) from Python. No Fortran or C expertise is required for using this tool.

The FLASH code is a modular, adaptive, parallel simulation code capable of handling general compressible flow problems in astrophysical environments. It has been designed to allow users to configure initial and boundary conditions, change algorithms, and add new physical effects with minimal effort. It uses the PARAMESH library to manage a block-structured adaptive grid, placing resolution elements only where they are needed most. It uses the Message-Passing Interface (MPI) library to achieve portability and scalability on a variety of different message-passing parallel computers.

Written with the noweb literate programming tool, BaseEncode provides a framework for portable encoding and decoding of data in text files, somewhat similar to uuencoded arithmetic coding. By using statistical knowledge, some amount of compression can also be achieved. The algorithm is designed to be highly portable: only 16-bit signed integers are assumed. Output comes in the form of a Fortran-90 module, but translation to other languages is trivial.

LAPACK is a linear algebra library, based on LINPACK and EISPACK, designed to provide routines for handling simultaneous equations and matrix algebra efficiently, particularly on shared memory vector processors, parallel processors, and clusters. The code is written in Fortran, and requires the BLAS (Basic Linear Algebra Subprograms) library.

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.

NOVAS (Naval Observatory Vector Astrometry Subroutines) is an integrated package of subroutines for the computation of a wide variety of common astrometric quantities and transformations. It can provide the instantaneous coordinates (apparent, topocentric, or astrometric place) of any star or planet, and also provides general astrometric utility transformations, such as those for precession, nutation, aberration, parallax, etc. It is useful for data reduction programs, telescope control systems, and simulations.

PFMD is a program that simulates the liquid state of a polarizable fluid by means of a dissociable potential applied in a Molecular Dynamics algorithm. Currently supported molecules are water (H2O) and MX3, where M is a metal chosen among Al, Fe, or Ga and X is a halogen among Cl, Br, or I.

The GotoBLAS codes are a fast implementation of the Basic Linear Algebra Subroutines. The advantage is fast calculation. Note that the actual performance depends in part on the code from which you call the GotoBLAS subroutine(s), and on the combination of architecture and operating system under which you are running. Your own tuning can make a big difference.