Xprintutil is a package of 4 printing utilities: xdvips (a frontend to dvips), xenscript (a frontend to enscript), xa2tex (a frontend to printing text files through TeX), and printer (a printer manager). All of these parse the /etc/printcap file and let the user interactively select the printer as well as most of the command line options of dvips and enscript.
X-Tract is an XML Script processor. XML Script is a fully XML compliant language, specifically designed for handling XML data. XML Script is more powerful than XSL, and can perform many XSL functions more efficiently. X-Tract can be used on the command line, or can be run from a web server to handle CGI queries.
WEEDS is a Java 1.1 application which converts XML files describing written to "limon.dtd" to an HTML-formatted flora. We wrote weeds to make our own flora of 32 plants we observed in the Dominican Republic, but we believe WEEDS would be immediately useful for anyone who wants to make a flora. Also, the design and much of the code could be adapted to many other applications such as online catalogs.
The iPerl interpreter is a transforming filter that works much like the C preprocessor or the m4 macro processor, only that the language embedded into a document is full powered Perl. iPerl documents consist of any kind of text to be output, and bits of specially-marked Perl that control the document with conditionals or loops spanning text, subdocument-includes, and macro definitions. This is comparable to but far more powerful than the C preprocessor or the m4 macro processor. It can also be seen as a template-mechanism.
tal aligns common characters at the ends of lines. This is especially useful for making long C macro definitions look nice or for repairing "broken" comment boxes. tal works on any kind of common ending, which it autodetects. Intended as, but not limited to being, a filter program ("plug-in") for text editors.