Berkeley DB (libdb) is a programmatic toolkit that provides embedded database support for both traditional and client/server applications. It includes b+tree, queue, extended linear hashing, fixed, and variable-length record access methods, transactions, locking, logging, shared memory caching, database recovery, and replication for highly available systems. DB supports C, C++, C#, Java, PHP, and Perl APIs. It supports key-value pair (NoSQL), SQL, and Java Object formatted data. It is available for a wide variety of Unix platforms as well as QNX, Android, Mac OS X, and several varieties of Windows.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
Clig uses a simple description file to create C-code to interprete the typical *NIX command line as well as an up-to-date usage-message and a manual page skeleton. It supports Flag, String, Int, Long, Float and Double types, with ranges, defaults, and more. The generated C-Code is ANSI but has been reported to work with C++. It is self contained code which does not depend on any library other than libc. Included is a TCL-only TCL-package to instrument your TCL scripts the same way as your C-programs.
e4Graph is a C++ library that allows programs to store graph-like data persistently and to access and manipulate that data efficiently. With e4Graph, you can arrange your data in the most natural form that reflects the relationships between its parts, rather than having to force it into a table-like format. The e4Graph library also allows you to concentrate on the relationships you want to represent, and not on how to store them in a database. You can modify data items, and add and remove connections and relationships between pieces of data on the fly. e4Graph allows you to represent an unlimited number of different connections between pieces of data, and your program can selectively manipulate the data according to the relationships it cares about, not having to know about other connections represented in the data set.
f/Calc is a utility to calculate lens formulae for photographers so you can focus on the artistic bits rather than on the mathematics behind it all. f/Calc can do "f" number arithmetic, and can calculate depth of field, hyperfocal distance, the field of view of a lens, the angle of view of a lens, magnification, and how the focal length of the lens on the camera changes the way the spot metering function works. In addition to the Unix/Linux Tcl/Tk version, there are native Windows, Palm OS, and Macintosh versions as well.
GNUlpr version 1.0 is a complete printing system based on LPR, and provides support for printer-specific options, GUI tools, and autoconfiguration. The 1.1 tree is a completely re-thought printing system. Rather than creating an all-powerful spooling daemon, it constructs a pipeline of "filter" programs to perform tasks (spooling, data stream type conversion, authentication, network protocols, etc.).