Eccellio Science - Search Engine - Firefox Addon - Eccellio is a Search Engine that brings a cool new feature, named "Faceted Classification", that easily allows finding exactly what you are looking for on the Net.
Eccellio uses Google power but it adds an extra level of classifications that allows you to refine your search easily
ImHalal.com web search - Firefox Addon - ImHalal is a search engine designed in respect of the culture of Muslims. The search engines algorithm differs from alternative search engines because the relevancy of the results are based on the culture, mindset and lifestyle of Muslims
CoboCards Pool - Create and study flashcards - alone or with your friends. Cobocards are virtually created flashcards. You can print them and study offline, edit them again and again, compare with older versions, check the status of your knowledge, upload pictures and graphs, include formula with LaTeX, share your flashcards with friends, set a deadline for exams,..
sequere.eu - Science - Firefox Addon - The "sequere.eu - Science" plugin enables a search of scientific information, articles, publications, full-text articles, abstracts, patents etc.
The sequere.eu search engine enables you to search in certain geopolitical regions, like EU, western, southern or eastern Europe
Neil's RPN Calculator - This Scientific calculator uses RPN Logic (Reverse Polish Notation) similar to the HP Engineering Calculator. For example: To add 2 and 3 use "2 Enter 3 +." Everytime you press Enter it adds the number to the stack
QDB - Firefox Addon - Search the Internet Quote Database (bash.org) directly from the Firefox search bar. Do you need more randomness in your life? Are you getting frustrated by the helpful and relevant results returned by conventional search engines? Some mindlessness from QDB may be just what you need