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.
f265 is a cross-platform HEVC/H.265 video encoder. The project initially targets high quality offline encoding, but it is not limited to this scope. It is designed from the ground up to maximize quality and performance in offline and real-time scenarios using recent hardware technology and interfaces such as the Intel® AVX2 instruction set.
Fabula is a Python game engine suitable for adventure, role-playing, and strategy games and digital interactive storytelling. It offers a client-server architecture, an event-based protocol, multiplayer and networking capabilities, a multi-threaded server, an abstract, visualization-agnostic model of a game world, an asset manager, and a plugin system. Gameplay can be recorded and played back. The code is well documented and runs on Linux and MS Windows (it should work on OS X, too, but this has not yet been tested). Fabula can be used as a library to develop your own games. As an alternative, you can use the included Pygame-based graphical editor and the default game engine.
faces is a powerful and flexible project management tool. It not only offers many extraordinary features like multiple resource balancing algorithms and multi scenario planing, but can also be easily extended and customized. Faces consists of a Python class framework and a graphical front-end.
fakedbfs is a suite of tools and a library for cataloguing files. Anything that is a file can be catalogued along with metadata. The metadata is then searchable through various querying facilities. It runs entirely in userland and was inspired by BFS, which doesn't do content indexing, only metadata.
Famflows is a program which tracks "flows" of energy and materials inside a household. It has an alternative approach from double entry accounting systems. In those systems (like gnucash or jgnash), the transactions are balanced in numeric value. In famflows, instead, the transactions are balanced in the conversion, but not in the numeric value.