minify-html
minify-html is a Wordpress plugin that does just what it says on the tin -- it will 'minify' the HTML output of your Wordpress blog. This means that superflous whitespace, HTML comments (but not conditional comments) and some other non-critical things will be removed from the markup. This results in less HTML being sent to the client, decreasing page load times and saving bandwidth.
I originally wrote this for use on a couple Wordpress-based sites that I administer, but figured that since the only other alternatives out there require PHP tidy to be installed, this might be useful to folks on shared hosting without PHP tidy or the htmltidy binary.
minify-html uses the Minify_HTML class of the excellent Minify library. As such, minify-html is licensed under the same license: the New BSD License.
You can download minify-html directly from this site.