Here are some Ruby gems I developed and published:
RBTxt2Html - A small gem to read a text file with some easy markup and convert it to HTML code. See it at GitHub, at RubyGems and see it's documentation.
SaneTitle - A gem to sanitize a string and prepare it to be used as a URL. It removes special characters, replaces spaces with hyphens and do some other preparations. If needed, it may truncate the size of the resulting string and also append the extension ".html" to it. See it at GitHub, at Rubygems and see it's documentation.