Liberalism VS Progressivism?

Here's a piece on Truthdig which addresses an interesting topic; the distinction, if there is one, between Liberalism and Progressivism. Is this a distinction without a difference or is there a basic difference in principle as the author claims?

Based on his definition I identify more with Progressivism, than Liberalism, kind of like shopping at a whole foods store rather than a candy store.

Though I got an "A" in macro economics I've forgotten much of what I memorized for the final.

Any economists out there who can help out here? Use the 'Comments' option at the end of the post.

Leanderthal