- Experts Exchange - thousands of experts answer technical questions, which are posted on site by subject area. Focus is on computer queries.
- Ask a Linguist - designed to be a place where anyone interested in language or linguistics can ask a question and get the response of a panel of professional linguists.
- Straight Dope, The - fighting ignorance since 1973 with answers to intriguing questions.
- AllExperts - covers a variety of topics including music, sports, health, love and romance, and more.
- Virtual Reference Desk - digital reference service offering an Internet-based question-and-answer service connecting users with subject experts.
- Ask the Experts - part of the My Virtual Reference Desk collection; provides links to a variety of experts in different fields.
- Ask an Expert Sources - links to experts in K-12 curricular related topics.
- Ask An Expert Page - get answers to questions about science, math, movies, the Internet, and more.
- AskForFree.com - advice given by email to specific questions in a variety of categories.
- Answer Guide - every month, National Geographic's Research Correspondence division answers several questions received via email.






