Freefile is a clone of the file(1) program that reads files and generates an educated guess about their contents. This version differs from implementations based on Ian Darwin's code in three ways: the source code is smaller, "file -z" can decode the contents of bzip2 files (and gzip files, which both implentations can handle), and it is GPL'ed. Freefile was originally written to resolve copyright issues about Ian Darwin's version, some of which still remain.
Ftwalk is a high level script programming language, very similar to awk, but greatly extended to include a richer type system, object-oriented features, 300+ built-in functions, extensibility through dynamic libraries, etc., which makes it roughly comparable to languages like Perl. It does file tree searches, and was originally used to implement selective redundant copy backup stores. It can be run interactively as a calculator.
FvwmKb is a module for Fvwm and Scwm window managers that makes it more comfortable to work with several Xkb keyboard layouts. For the focused window it stores the currently locked Xkb group (keyboard layout) in its internal database and restores it when the window is focused again making an impression that different windows simultaneousely have different selected keyboard layouts. It tells the window manager to reflect the currently locked Xkb group in the window decoration making it possible to tell which windows have which locked groups easily.