GRASS (the Geographic Resources Analysis Support System) is a software raster- and vector-based GIS (Geographic Information System), image processing system, graphics production system, and spatial modeling system. It contains many modules for raster data manipulation, vector data manipulation, rendering images on the monitor or paper, multispectral image geocoding and processing, point data management and general data management. It also has tools for interfacing with digitizers, scanners, and the PostgreSQL, DBF, and ODBC connected databases. GRASS operates on all common operating systems.
The GOBLIN project consists of a C++ class library for a large series of graph optimization problems, GOSH, an extension of the Tcl/Tk scripting language to graph objects, and GOBLET, a graphical user interface to the library functions. GOBLET includes a graph editor and supports the standard graph layout methods.
prerex is an interactive (command-line) editor and a LaTeX macro support package that can be used to create very attractive and readable prerequisite charts. A graphical front-end for the editor also provides a prerex-enabled PDF viewer. A prerequisite chart is a network of course boxes linked by prerequisite and co-requisite arrows.
JSBSim is a multi-platform flight dynamics model. The FDM is essentially the physics/math model that defines the movement of an aircraft under the forces and moments applied to it using the various control mechanisms and from the forces of nature. JSBSim has no native graphics. It can be run by itself as a standalone program, taking input from a script file and various aircraft configuration files, or it can be run as an integrated part of a larger flight simulator implementation that includes a visual system. The most notable usage example is the FlightGear simulator. JSBSim models the aerodynamic forces and moments by the classic coefficient buildup method.
Ccide reads C, C++, BASIC, or bash source code containing embedded decision tables from stdin, expands the tables, copies the remaining statements, and forms a compilable C or C++ source module, executable bash script, or interpretable BASIC program. Erratic side effects are avoided by evaluating all condition expressions at exactly the same time, and by performing all evaluations and actions in the original sequence.
Vocatra is a console-based vocabulary trainer. It takes one or more vocabulary files, queries you for each word, and lets you try to give the correct answer. You can enable different learning modes. If you prefer to learn sequentially it has an order mode. Otherwise, there is also a random mode available.
BDDs [bry86] (or more precisely ROBDDs) are efficient data structures for representing a boolean formula. They are widely used in formal verification, in particular symbolic model-checking. Ruby- BDD, based on Buddy, provides access to BDDs from Ruby, a powerful and very easy to use object-oriented language. The purposes are quick prototyping and education.
Kallimachos is a simple Web-based digital book-catalog intended for personal use. Books are indexed by title, author, translator, edition, genre, page number, and ISBN. You can insert a new book, enter the library, and search by any item. It also provides a system-info viewer. The installation is quick and simple, and the program has a user-friendly interface.
Open Source Astronomy is a comprehensive collection of astronomy software packages built for Linux, Mac OS X, and Windows. Each collection comprises approximately 5GB of software. An installation assistant is included along with a browsable documentation library covering all included packages.