TRIP is a general computer algebra system dedicated to celestial mechanics. It includes a numerical kernel and has interfaces to gnuplot and xmgrace. Computations can be performed with double, quadruple, or multi-precision. Users can dynamically load external libraries written in C, C++, or Fortran. Parallel computations on multivariate polynomials can be performed.

QCAD is an application for computer aided drafting (CAD) in two dimensions (2D). With QCAD, you can create technical drawings such as plans for buildings, interiors, mechanical parts, or schematics and diagrams. QCAD can be easily extended through plugins and its very powerful and complete ECMAScript (JavaScript) interface.

Armadillo is a C++ linear algebra library (matrix maths) aiming towards a good balance between speed and ease of use. The API is deliberately similar to Matlab's. Integer, floating point, and complex numbers are supported, as well as a subset of trigonometric and statistics functions. Various matrix decompositions are provided through optional integration with LAPACK and ATLAS numerics libraries. A delayed evaluation approach, based on template meta-programming, is used (during compile time) to combine several operations into one and reduce or eliminate the need for temporaries.

Gwyddion is a modular SPM (Scanning Probe Microsope) data visualization and analysis tool. It can be used for all most frequently used data processing operations including: leveling, false color plotting, shading, filtering, denoising, data editing, integral transforms, grain analysis, profile extraction, fractal analysis, and many more. The program is primarily focused on SPM data analysis (e.g. data obtained from AFM, STM, NSOM, and similar microscopes). However, it can also be used for analyzing SEM (scaning electron microscopy) data or any other 2D data.

GNU units converts quantities expressed in various systems of measurement to their equivalents in other systems of measurement. Like many similar programs, it can handle multiplicative scale changes. It can also handle nonlinear conversions such as Fahrenheit to Celsius, and it can perform conversions from and to sums of units, such as converting between feet plus inches and meters. Beyond simple unit conversions, units can be used as a general-purpose scientific calculator which keeps track of units in its calculations. You can form arbitrary complex mathematical expressions of dimensions including sums, products, quotients, powers, and even roots of dimensions. In this way, you can ensure accuracy and dimensional consistency when working with long expressions which involve many different units which may combine in complex ways. The units are defined in an extensive, well-annotated data file which defines over 2,500 units. You can also provide your own file to supplement or replace the standard file.