trf is an extension library to the script language tcl, as created by John Ousterhout. It extends the language at the C-level with so-called "transformer"-procedures. With the help of some patches to the core the package is able to intercept all read/write operations on designated channels, thus giving it the ability to transform the buffer contents as desired. Existing transforms include Base64, UUencode, Hashes (SHA, MD5, ...), error correction codec, zlib-based compression, script level transforms.
This package includes freecell, golf, mastermind, merlin, minesweeper, pegged, solitaire, taipei, and thornq, plus a solitaire toolkit so that you can write your own games. These games are modelled after the Windows(tm) versions, with several enhancements, including a more colorful "Linux-y" theme.
GRPN is a RPN calculator for the X Window system built using the GIMP Toolkit (GTK). GRPN works with real numbers, complex numbers, matrices, and complex matrices. Numbers can be displayed in 4 different radix modes, and complex numbers can be displayed in either Cartesian or polar form, in decimal or engineering notation.
gpsd is a daemon that listens to a GPS or Loran receiver and translates the positional data into a simplified format that can be more easily used by other programs, like chart plotters. The package comes with a sample client that plots the location of the currently visible GPS satellites (if available) and a speedometer. It can also use DGPS/ip.