Sanzang is a compact and simple cross-platform machine translation system. It is especially useful for translating from the CJK languages (Chinese, Japanese, and Korean), and it is very suitable for working with ancient and otherwise difficult texts. Unlike most other machine translation systems, Sanzang is small and approachable. Any user can develop his or her own translation rules, and these rules are simply stored in a text file and applied at runtime.
Winnow efficiently trains and operates any number of unique Bayesian (Naive Bayes) classifiers on large sets of content. It has very high performance and works with very small training and unbalanced training sets. It has been used to power an innovative Web feed reader that uses smart tags, which learn and find the content you want to see, from more sources than you can follow with traditional feed readers. It works particularly well with Ruby and Ruby on Rails.
Rbpar is a program and an accompanying library suite designed for formatting text paragraphs. In this sense, it greatly resembles the venerable Unix programs fmt and par. The difference is that rbpar sports a more modern design: it is written completely in Ruby and offers an internal API for several paragraph formatting tasks.
tbibtools provide a simple regexp-based BibTeX parser that can be used to sort bib files, reformat bib files, list keys in a bib file, and show bib entries matching a regular expression. It is available as both a script and a VIM plugin. It makes a few assumptions about how a bib file should look like.
Rextile allows you to build XHTML documents and entire Web sites with ease. You write text using Textile (a format much more concise than XHTML), automate document parts with Ruby scripting, and generate the site offline (the server gets static XHTML). Rextile was inspired by Xilize. It uses RedCloth to convert Textile to XHTML, erb to run script blocks, and Hpricot for DOM manipulation.