Probably the single most challenging problem in computer science is to develop computers that can understand natural languages. So far, the complete solution to this problem has proved elusive, although a great deal of progress has been made. Fourth-generation languages are the programming languages closest to natural languages.

Speech Research Links 
Excellent collection of speech related resources on the Web.

The Natural Language Software Registry home page 
This online research server contains links to several language processing software pages containing detailed product descriptions.

ACL Special Interest Group on Natural Language Generation (SIGGEN)
Provides information about the area of natural language generation, including software, people, places, current research, and archives.

Center for Machine Translation research site
Contains information on the research activities and reports from the Center for Machine Translation/Language Technologies Institute located in the School of Computer Science at Carnegie Mellon University.

Yahoo!'s natual language processing page
Yahoo!'s directory of natural language processing.

Human Language Technology Survey
Contains links to the table of contents for the "Human Language Technology Survey " project. Sections include: spoken and written language input, language analysis and understanding, spoken output technologies, document processing, and language resources.

Natural language database query tools
Home page for ELF Software Co., developer of natural language database query tools.

Natural language processing FAQ
Contains links to FAQs focusing on natural language processing, speech and linguistics.

Yahoo!'s natural language processing institutes page
Yahoo!'s directory of natural language processing institutes.