The search engine has been around for more than 20 years. Since then many have come, gone or lost popularity. Today the king of all engines is the big G or Google. It has become so popular that we no longer say "search it" but instead opt for "Google it". There are many people that are no longer entering URLs directly in their browser's address bar, but rather searching for it and hitting the first result!
Google is a very powerful engine, no question about it. You can search for pages, images, news, videos, locations, locations, books, patents, products, applications, discussions, academic journals and more, all from a single page. You can even convert between currencies or use it as a calculator!
Google isn't everything, there are alternative engines (here is one I reviewed called DuckDuckGo) that may not be as big as Google, but rather cover a certain topic or specialty. Here are some I found (and used):
Traditional Search Engines
- DuckDuckGo: A competitor to the other popular engines out there such as Google, Bing, Yahoo! etc… The difference is that they do not collect information on your searches like the others. Offers better privacy and no bubbling (basing results on your previous searches).
Metasearch Engines (looks up multiple engines)
- Dogpile: I once used this engine many years ago. It searches on Google, Bing and Yahoo! Next to the URL of each result, it mentions from where it pulled the result.
Health and Medical Stuff
- WebMD: You can search for the disease you are suffering from, or by symptoms if you don't know what's wrong. It looks more like a portal rather than engine, with links on the home page itself. You can also find doctors (US only), drugs (the medical kind…) and health tools.
- Technorati: This one is one of the best blog search engines (apart from Google blog search) that has been around for quite some time. You can search or just surf through the links to search for blogs by category or tags and so on.
DIYs / Tutorials
- eHow: This one constantly comes up on search results that may be related to a tutorial of some kind. You get an article written by a contributor on how to do something.
- wikiHow: Similar to eHow and also one that pops up regularly on results page of engines. Here is a dangerous article!
Computational Knowledge Engines
- WolframAlpha: I believe it is the best engine publicly available in this category. Unlike regular engines it will usually come up with a single result for queries. You do not exactly enter a question or a bunch of keywords. Rather ask it what you want to know, try these keywords for example: pi, blue+yellow or any of these hundreds of examples they have.