PhysicsFS is a library to provide abstract access to various archives. The programmer defines a "write directory" on the physical filesystem. No file writing done through the PhysicsFS API can leave that write directory, for security. For file reading, the programmer lists directories and archives that form a "search path". Once the search path is defined, it becomes a single, transparent, hierarchical filesystem. This makes for easy access to ZIP files in the same way as you access a file directly on the disk, and it makes it easy to ship a new archive that will override a previous archive on a per-file basis. Symbolic links can be disabled, for added safety. Finally, PhysicsFS gives you a platform- abstracted means to determine if CD-ROMs are available, the user's home directory, where in the real filesystem your program is running, etc.
Ruby/Password is a set of useful methods for creating, verifying, and manipulating passwords. It includes an interface to CrackLib, a library commonly used for checking password strength. It is intended to be used by system administrators who need to write Ruby programs that prompt for, generate, verify, and encrypt passwords.
Marathon is a GUI test tool that allows you to play and record scripts against a Java Swing UI. It's written in Java, and uses Python and Ruby as its scripting language (the emphasis being on an extremely simple, readable syntax that customers/testers/analysts feel comfortable with). Marathon includes a recorder, editor, player, and debugger to simplify working with test scripts.
Makecheque is a tool (written in Ruby) to print bank cheques, either using bank-supplied stationey, or blank check paper (in conjuntion with a MICR font and perhaps special laser toner). It is intended to be used as part of an interactive bookkeeping system. Makecheque quickly and easily prints large batches of checks based on textual format specifications given as standard input and emits ready-for-printer Postscript on standard output.
rb.log is a full-featured weblogger written in Ruby. It features file uploads, comments, blog- rolling, side-bar editing, bookmarklets, the Blogger API, searching, RSS syndication, and archives. It also performs well on slower machines by regenerating static pages after posts are made.