• Academic Info Subject Index
• Best Information on the Net
• Beyond Bookmarks: Schemes for Organizing the Web by Subject    
• BUBL Link
• Columbia University E-Guides
• CyberDewey Subject Collection
• DMOZ: Open Directory Project
• InfoMine
• The Internet Public Library
• Internet Scout Report Archives
• Librarian's Internet Index
• The Michigan Electronic Library
• NISS Information Gateway: Directory of Networked Resources (UK)
• PINAKES - A Subject Launchpad
• RiceInfo: Internet Navigation Tools
• Resource Discovery Network
• Reference Shelves on the Internet
• Subject-Based Information Gateways
• Subject Guide: University of California, Irvine

 See also subject sections at various Singular Internet Search Engines:

• About.com
• Yahoo (see subject structure section)
• Beaucoup (See subject list section)

• AllExperts
• AskJeeves
• Ask Joan of Art
• DeskRef
• Google Scholar (Beta)
• Internet Public Library Reference Collection  
• I-Tools: Research It
• Library Spot
• Ref Desk.com
• Internet Library for Librarians
• Internet Scout Project
• Librarians Index to the Internet
• Pitsco's Ask an Expert
• THOR: The Virtual Reference Desk
• Virtual Reference Desk
• World Health Organization Research Tools
• WWW Virtual Library