The Guava tools are a set of Perl scripts for HTML pre-processing. You can create multi-page documents with contents tables, or use templates to give a consistent look to a set of pages. All output is passed through the C preprocessor, so you can use directives such as #include, #define and #if. There are also built-in macros for producing dates, cross references, etc.
HCC is character filter which replaces certain characters by other characters one by one, according to a translation table. It is useful for converting plain texts from one character set to another. Currently available filters include win1250 to ISO-8859-2, win1250 to ASCII (ISO-8859-1), ISO-8859-2 to win1250, and ISO-8859-2 to ASCII (ISO-8859-1). You may get better results with "iconv" utility which is part of glibc.
Harvest is a system to collect information and make it searchable using a Web interface. It can collect information using HTTP, FTP, NNTP, and local files. Supported formats include HTML, DVI, PS, fulltext, mail, man pages, news, troff, WordPerfect, C sources, and many more. Adding support for new formats is easy due to Harvest's modular design.
Hasciicam makes it possible to have live ASCII video on the Web. It captures video from a TV card and renders it into ASCII, formatting the output into an HTML page with a refresh tag or in a live ASCII window or in a simple text file as well, giving anyone that has a bttv card, a Linux box, and a cheap modem line the ability to show a live asciivideo feed that can be browsable without any need for a plugin, Java, etc.
Hodie prints the current date and time to stdout in Roman numerals, with grammatically correct Latin. Complete with Id., Kal., Non., pridie, postridie, bis, and all the other nice annoyances. As an option, it even provides you with current date according to Roman calendar -- that is 'ab urbe condita'; after Rome was built.