The GNU Scientific Library (GSL) is a collection of routines for scientific computing. It covers a wide range of numerical routines and is in principle relatively easy to use.

LAPACK is a Fortran library for numerical computations in linear algebra. Excellent performance and many specialized algorithms make it very popular within the scientific community.

The beamer document class brings presentation design to LaTeX. Beamer presentations are created very similarly to usual documents, thus offering the whole features of the LaTeX typesetting sytem.

Maxima is a full-fledged computer algebra system for symbolic and numeric calculations. It provides many functions from different areas of mathematics, and new ones can be added easily.

Octave is a program for numerical computations. It provides many functions from all fields of numerical mathematics, including differentiation, integration, linear algebra and solving of nonlinear equations. Its syntax is mostly Matlab compliant.

Pybligrapher is an application for managing bibliography databases. It supports several file formats and offers a customizable user interface.

Xd3d is a package for advanced 2D and 3D visualization. It is mainly aimed for applications in science and engineering and supports various input formats.

Xfig is a graphics program that allows a fast creation of technical and scientific figures. Exporters for various formats guarantee a painless integration with other software, e.g. LaTeX.

The pst-pdf package for LaTeX offers an easy way to create PDF files from documents containing PostScript images or native PostScript commands. Apart from including the package and using a shell script to build the PDF file no further steps are required.