- Science Dictionary - A science search engine, which pulls data from scientific web sites.
- ISI Highly Cited - A search tool to identify individuals, departments and laboratories that have made fundamental contributions to the advancement of science and technology in recent decades.
- CiteSeer - Scientific literature digital library and search engine.
- Scirus - Search engine that fetches only scientific websites.
- Online Journals Search Engine - A multi-search tool that permits queries of a number of scientific journals.
- Article Sciences - Scientific article search and order engine, a service provided by Institut de l'Information Scientifique et Technique (INIST) of Centre National de la Recherche Scientifique (CNRS), France.
- WorldWideScience - A search which uses multilateral partnerships to search national and international databases.
- Science-advisor.net - Scientific search engine and online forum. Researchers and students can search the scientific literature and can freely and anonymously discuss and review research articles.
- MyNetResearch.com - Allows researchers worldwide to collaborate, manage projects, stay informed about the latest research developments in their subject specializations, and use specialist tools to help them with research.