Constructed Languages
- A description of constructed languages with categories and examples.
- http://en.wikipedia.org/wiki/Artificial_language

Conlang Profiles at LangMaker.com
- A regularly updated directory of over 1,100 invented languages and neographies.
- http://www.langmaker.com/

Bartlett's Unfamiliar Model Language
- Summaries of lesser known modular languages written by Paul Bartlett. Afrihili, Eurolengo, Frater, Oz and Tutonish.
- http://www.langmaker.com/Bartlett.htm

The ConScript Directory
- A directory of invented writing systems for artificial languages.
- http://www.sedesdraconis.com/index.cgi?ConScript

Planlingvoj
- Links to planned languages compiled by the Esperantist Donald J. Harlow.
- http://www.webcom.com/~donh/conlang.html

Language Guides
- Huge resource material for natural as well as constructed languages.
- http://babel.uoregon.edu/yamada/guides.html

Constructed Human Languages
- Categorized links to information about constructed languages.
- http://www.quetzal.com/conlang.html