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.
HTML PLAIN is a "HTML Preprocessor Lacking An Interesting Name". Symbolic names instead of filenames allows files to be moved around without breaking links. Templates allow easy customization and changes of the layout. Tags can be redefined for a better structure of the document. Beginners can use one of the given templates and do not have to use any markup language at all. Experts can write their own Perl macros in order to get access to metadata and more flexibility.
HTML-XML-utils consists of a set of small C programs (filters) that read HTML and XML files and can add a table of contents, an alphabetical index, a bibliography, cross-references, numbered headings, remove elements, count elements, pretty-print them, etc. When it reads HTML, it assumes the code is correct HTML 4.0 or close to it.