Alta Vista Alta Vista covers a huge number of web sites and has many powerful features for limiting searches. Northern Light Northern Light also covers a large number of sites. Google A simple, uncluttered but highly comprehensive search engine. These tools search a universe of web sites that have already been pre-selected by people who have looked at and evaluated them. Because of this, the sites retrieved will generally be of higher quality.
Biographical information describing the expert's background is given.
Sites can be searched or browsed. Categories can be browsed or searched. Yahoo A very large and popular directory. Most sites are added by users who suggest them. Can be browsed or searched.