make_html2text.sh converts all HTML (.html and .htm) files in the
current directory into text files (.txt). For each HTML file, it
verifies that the text file does not exists, or is older than the
corresponding HTML file; if the text file is more recent, nothing is
done.

To use this script, you will have to install the program html2text.
The option -nobs is used to avoid output of formatting sequences (bold,
italic, etc.).