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.
FormValidator is a Ruby port of Perl's Data::FormValidator library. It makes it easy to validate data coming in from HTML forms by providing a robust set of methods to handle required fields, dependent fields, filtering, constraints, tainting, and defaults. Its modular design allows you to easily add your own filters and constraints and also lets you to keep validation data outside of your CGI scripts.
The lptools suite provides a complete, programming-language independent, literate programming environment. The suite targets XML documentation, but the underlying system has no bias that would disadvantage other documentation languages. It also includes a programmable build tool (a replacement for 'make') that can handle very complex and dynamic dependency graphs.