HTMLDOC is a program that reads HTML and Markdown source files or web pages and generates corresponding EPUB, HTML, PostScript, or PDF files with an optional table of contents.
HTMLDOC was developed in the 1990’s as a documentation generator for my previous company, and has since seen a lot of usage as a report generator embedded in web servers. However, it does not support many things in “the modern web”, such as:
Cascading Style Sheets (CSS): While I have experimented with adding CSS support to HTMLDOC, proper CSS support is non-trivial especially for paged output (which is not well supported by CSS)
Encryption: HTMLDOC currently supports the older (and very insecure) PDF 1.4 (128-bit RC4) encryption. I have looked at supporting AES (256-bit) encryption, however it is not widely supported and there are incompatible changes in PDF 2.0, so it is unlikely to be added to HTMLDOC.
Forms: HTML forms and PDF forms are very different things. While I have had many requests to add support for PDF forms over the years, I have not found a satisfactory way to do so.
Tables: HTMLDOC supports HTML 3.2 tables with basic support for TBODY and THEAD.
Unicode: While HTMLDOC does support UTF-8 for “Western” languages, there is absolutely no support for languages that require dynamic rewriting or right-to-left text formatting. Basically this means you can’t use HTMLDOC to format Arabic, Chinese, Hebrew, Japanese, or other languages that are not based on latin-based alphabets that read left-to-right.
Emoji: The fonts bundled with HTMLDOC do not include Unicode Emoji characters.
My focus is on addressing security, build, and formatting issues and not on extending HTMLDOC to support CSS or full Unicode.
HTMLDOC is provided under the terms of the GNU General Public License version 2.