Garbl's Writing Center is an impressive collection of on-line resources for writers. Besides collecting links to resources all over the Web, it contains its own style manual and concise-writing guide. It's maintained by Gary B. Larson, who says that GWC "reflects my commitment to my growth, to clear, concise, and useful writing and to helping others improve their writing. I believe the Internet, used responsibly, has the power and potential to enhance our communication and citizen action."
Warning: GWC includes some political messages, especially on the home page, with which you may agree or disagree. Gary is an unapologetic lefty, and uses GWC to advertise his views in strong language. He says, "I support liberal, progressive candidates, campaigns
and causes: peace and disarmament, environmental protection,
public education, public transportation, economic opportunity,
and civil, equal and human rights." He's not a fan of the current administration.