Signify is a neat little program that allows a random signature to be generated from a set of rules. Each "section" can be one of an unlimited number of possibilities, each with its own weighting so those really cool quotes can appear more often than others. Sections can also be placed next to each other vertically to create columns. Each section can be formatted independently as left/right/center and top/bottom/vcenter.

Bats is a TAP-compliant testing framework for Bash. It provides a simple way to verify that the UNIX programs you write behave as expected. Bats is most useful when testing software written in Bash, but you can use it to test any UNIX program.

BindGraph is a very simple DNS statistics RRDtool frontend for BIND9 that produces daily, weekly, monthly and yearly graphs of the DNS server's activity (queries, errors, etc.).

OpenSCAD is a software for creating solid 3D CAD objects. It focuses on CAD aspects rather than artistic ones.

WML (Website META Language) is a free and extensible Webdesigner's off-line HTML generation toolkit for Unix. WML consists of a control frontend driving up to nine backends in a sequential pass-oriented filtering scheme. Each backend provides one particular core language. For maximum power WML additionally ships with a well-suited set of include files which provide higher-level features build on top of the backends core languages. While not trivial and idiot proof WML provides most of the core features real hackers always wanted for HTML generation.

Pngcrush is an optimizer for PNG (Portable Network Graphics) files. Its main purpose is to reduce the size of the PNG IDAT data stream by trying various compression levels and PNG filter methods. It also can be used to remove unwanted ancillary chunks, or to add certain chunks including gAMA, tRNS, and textual chunks.