Opera (Web browser)

Opera is a web browser and Internet suite developed by the Opera Software company. Opera handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, IRC online chatting, downloading files via BitTorrent, and reading web feeds. Opera is offered free of charge for personal computers and mobile phones, but for other devices it must be paid for.

Features of Opera include tabbed browsing, page zooming, mouse gestures, and an integrated download manager. Its security features include built-in phishing and malware protection, strong encryption when browsing secure web sites, and the ability to easily delete private data such as cookies and browsing history by simply clicking a button.

Opera runs on a variety of personal computer operating systems, including Microsoft Windows, Mac OS X, Linux, FreeBSD, and Solaris. Though evaluations of Opera have been largely positive, Opera has captured only a fraction of the worldwide personal computer browser market.

Opera has a stronger market share, however, on mobile devices such as mobile phones, smartphones, and personal digital assistants. Editions of Opera are available for devices using the Symbian and Windows Mobile operating systems, as well as Java ME-enabled devices. In fact, approximately 40 million mobile phones have shipped with Opera pre-installed. Furthermore, Opera is the only commercial web browser available for the Nintendo DS and Wii gaming systems. Some television set-top boxes use Opera as well, and Adobe licensed Opera technology for use in the Adobe Creative Suite.

URI scheme-Uniform Resource Identifier

In the field of computer networking, a URI scheme is the top level of the Uniform Resource Identifier (URI) naming structure. All URIs and absolute URI references are formed with a scheme name, followed by a colon character (":"), and the remainder of the URI called (in the outdated RFCs 1738 and 2396, but not the current STD 66/RFC 3986) the scheme-specific part. The syntax and semantics of the scheme-specific part are left largely to the specifications governing individual schemes, subject to certain constraints such as reserved characters and how to "escape" them.

URI schemes are sometimes erroneously referred to as "protocols", or specifically as URI protocols or URL protocols, since most were originally designed to be used with a particular protocol, and often have the same name. The http scheme, for instance, is generally used for interacting with Web resources using HyperText Transfer Protocol. Today, URIs with that scheme are also used for other purposes, such as RDF resource identifiers and XML namespaces, that are not related to the protocol. Furthermore, some URI schemes are not associated with any specific protocol (e.g. "file") and many others do not use the name of a protocol as their prefix (e.g. "news").

URI schemes should be registered with IANA, although non-registered schemes are used in practice. RFC 4395 describes the procedures for registering new URI schemes.

The World Wide Web Consortium

The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (abbreviated WWW or W3). It is arranged as a consortium where member organizations maintain full-time staff for the purpose of working together in the development of standards for the World Wide Web. As of February 2008, the W3C had 434 members.W3C also engages in education and outreach, develops software and serves as an open forum for discussion about the Web. It was founded and is headed by Sir Tim Berners-Lee.

Spreadsheet

A table of values arranged in rows and columns. Each value can have a predefined relationship to the other values. If you change one value, therefore, you may need to change other values as well.

Spreadsheet applications are computer programs that let you create and manipulate spreadsheets electronically. In a spreadsheet application, each value sits in a cell. You can define what type of data is in each cell and how different cells depend on one another. The relationships between cells are called formulas, and the names of the cells are called labels.

Once you have defined the cells and the formulas for linking them together, you can enter your data. You can then modify selected values to see how all the other values change accordingly. This enables you to study various what-if scenarios.

Mosaic (web browser)

Mosaic is the web browser credited with popularizing the World Wide Web. It was also a client for earlier protocols such as FTP, Usenet, and Gopher. Its clean, easily understood user interface, reliability, Windows port and simple installation all contributed to making it the application that opened up the Web to the general public. Mosaic was also the first browser to display images inline with text instead of displaying images in a separate window.

Mosaic was developed at the National Center for Supercomputing Applications (NCSA) beginning in late 1992. NCSA released the browser in 1993, and officially discontinued development and support on January 7, 1997. However, it can still be downloaded from NCSA.

Mosaic was the final link in the chain of technologies (TCP, IP, ftp | nntp | gopher | http, URL, HTML, etc.) which Tim Berners-Lee had earlier brought together to invent the World Wide Web. After the appearance of Mosaic the concept of the World Wide Web took off globally at an explosive rate.

ViolaWWW

Viola WWW, first developed in the early 1990s, was the first popular WWW web browser (though to a limited audience) which, until Mosaic, was the most frequently used web browser for access to the World Wide Web.Gillies and Cailliau in How the Web was Born offer an extensive history of the development of Viola. Viola was the invention of Pei-Yuan Wei, who at the time was a student at the University of California, Berkeley.

Created in 1992, it was the first browser to use authoring technology such as embedded script able objects, style sheets, and tables. According to Gilles and Cailliau "Viola was to become the first X-browser to make any impact, but even his early versions went down well at CERN...As this Viola WWW developed, it was to set the standard for everything to follow it." Ed Kroll also highlighted it in his popular 1992 text, Whole Internet User's Guide and Catalog.

Cascading Style Sheets

Cascading Style Sheets (CSS) is a style sheet language used to describe the presentation of a document written in a markup language. Its most common application is to style web pages written in HTML and XHTML, but the language can be applied to any kind of XML document, including SVG and XUL.

CSS can be used locally by the readers of web pages to define colors, fonts, layout, and other aspects of document presentation. It is designed primarily to enable the separation of document content (written in HTML or a similar markup language) from document presentation (written in CSS). This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, and reduce complexity and repetition in the structural content (such as by allowing for table less web design).