xless allows you to view information in an X window. It allows filename (or multiple filenames) arguments, or input via STDIN. It can print the current buffer and do regular expression searches.

SpamBayes uses a different set of algorithm to most statistical spam filters, which enables to dramatically lower the number of legitimate mail classified as spam, through the introduction of an 'unsure' category.

Despite the NP completeness of the satisfiabilty problem of Boolean formulas (SAT), SAT solvers are often able to decide this problem in a reasonable time frame. As all other NP complete problems are reducible to SAT, the solvers have become a general purpose tool for this class of problems.

Plait (pronounced "play") is a command-line jukebox and music player front end. It understands brief, easy to type queries that pick a single song, mix queries that combine works from multiple artists, stream queries that find Shoutcast radio streams, and everything in between.

Granite is an extension of GTK+. Among other things, it provides complex widgets and convenience functions designed for use in apps built for elementary OS.

hledger is a haskell port and friendly fork of John Wiegley's ledger accounting tool. This package provides a web interface as an alternative to the hledger command line interface.