The c-tree Plus embedded database engine offers developers several APIs that provide low-level routines, ISAM-level control, and higher-level interfaces. c-tree Plus is distributed in complete C source, has been ported to 100+ environments and includes a robust database Server SDK. It can be used to develop single user and peer-to-peer applications, or the client-side for applications using FairCom's database server, the c-tree Server.
tkxinput contains Xi, a library that adds Xinput management capabilities to the Tk toolkit, and a utility named calibrate that can be used to test various aspects of the Xinput configuration of an X server. calibrate can be used, as its name implies, as a touchscreen calibration facility.
Calc is arbitrary precision arithmetic system that uses a C-like language. It's useful as a calculator, an algorithm prototype, and as a mathematical research tool. More importantly, calc provides a machine-independent means of computation. Calc comes with a rich set of builtin mathematical and programmatic functions.
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.
Jmx4Perl provides an alternate way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Web application deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own programs. It also includes a Nagios plugin, check_jmx4perl, a jmx4perl command line tool for remote JMX queries and operations, and a readline-based JMX shell j4psh, with context sensitive command completion and syntax highlighting.