Information Retrieval and Web Search: Reference Resources

Computer Sciences is an award-winning free and open access educational video lectures repository. The lectures are given by distinguished scholars and scientists at the most important and prominent events like conferences, summer schools, workshops and science promo, ional events from many fields of Science. The portal is aimed at promoting science, exchanging ideas and fostering knowledge sharing by providing high-quality didactic contents not only to the scientific community but also to the general public. All lectures, accompanying documents, information and links are systematically selected and classified through the editorial process taking into account also users' comments.

Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. It tackles math, science, computer programming, history, art history, economics, and more. This site is also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

Digital Library of Mathematical Functions

Digital Handbook of mathematical functions with formulas, graphs, and mathematical tables. Managed by the National Institute of Standards and Technology.

FOLDOC  

It includes definitions of acronyms, jargon, programming languages, tools, architecture, operating etc.

Computer Desktop Encyclopedia 

CDE has been around and evolving since 1978.  This online version contains over 25,000 technical terms and phrases, 3,000 images, and 40,000 cross references,  It covers all aspects of computing, from chips to supercomputers and from command examples to mini-tutorials. It's free and there's no advertising.

Webopedia 

Webopedia is an online dictionary of computer- and Internet-related terms.