computer science

Internet Explorer

Internet Explorer is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Internet Explorer rather than just read about it. In short: Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a retired series of graphical web browsers developed by Microsoft that were used in the Windows line of operating systems. While IE has been discontinued on most Windows editions, it remains supported on certain editions of Windows, such as Windows 10 LTSB/LTSC.

Key takeaways

Internet Explorer belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Internet Explorer to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Internet Explorer from memory before moving on to harder problems.

Reference excerpt

Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a retired series of graphical web browsers developed by Microsoft that were used in the Windows line of operating systems. While IE has been discontinued on most Windows editions, it remains supported on certain editions of Windows, such as Windows 10 LTSB/LTSC. Starting in 1995, it was first released as part of the add-on package Plus! for Windows 95 that year. Later versions were available as free downloads or in-service packs and included in the original equipment manufacturer (OEM) service releases of Windows 95 and later versions of Windows. Microsoft spent over US$100 million per year on Internet Explorer in the late 1990s, with over 1,000 people involved in the project by 1999. In 2015, Microsoft Edge was released to succeed Internet Explorer 11 as Microsoft's primary web browser. New feature development for Internet Explorer was discontinued the following year, and support for the browser officially ended on June 15, 2022, for Windows 10 Semi-Annual Channel (SAC) editions. Although Internet Explorer has fallen out of general use after retirement, it was once the most widely used web browser, attaining a peak of 95% usage share by 2003. This came after Microsoft used bundling to win the first browser war against Netscape, which was the dominant browser in the 1990s. Its usage share declined with the launches of Firefox (2004) and Google Chrome (2008) and with the growing popularity of mobile operating systems such as Android and iOS that do not support Internet Explorer. Microsoft Edge, IE's successor, first overtook Internet Explorer in terms of market share in November 2019. Versions of Internet Explorer for other operating systems were also produced, including an Xbox 360 version called Internet Explorer for Xbox and for platforms Microsoft no longer supports: Internet Explorer for Mac and Internet Explorer for UNIX (Solaris and HP-UX), and an embedded OEM version called Pocket Internet Explorer, later rebranded Internet Explorer Mobile, made for Windows CE, Windows Phone, and, previously, based on Internet Explorer 7, for Windows Phone 7. The browser was scrutinized throughout its development for its use of third-party technology (such as the source code of Spyglass Mosaic, used without royalty in early versions) and security and privacy vulnerabilities, and the United States and the European Union have determined that the integration of Internet Explorer with Windows has been to the detriment of fair browser competition. The core of Internet Explorer 11 will continue being shipped and supported until at least 2029 as IE Mode, a feature of Microsoft Edge, enabling Edge to display web pages using Internet Explorer 11's Trident layout engine and other components. Through IE Mode, the underlying technology of Internet Explorer 11 partially exists on versions of Windows that do not support IE11 as a proper application, including newer versions of Windows 10, as well as Windows 11 21H2-25H2, Windows Server 2022 and Windows Server 2025.

History

Internet Explorer 1

The Internet Explorer project was started in the summer of 1994 by Thomas Reardon, who, according to former project lead Ben Slivka, used source code from Spyglass, Inc. Mosaic, which was an early commercial web browser with formal ties to the pioneering National Center for Supercomputing Applications (NCSA) Mosaic browser. In late 1994, Microsoft licensed Spyglass Mosaic for a quarterly fee plus a percentage of Microsoft's non-Windows revenues for the software. Although bearing a name similar to NCSA Mosaic, Spyglass Mosaic had used the NCSA Mosaic source code sparingly. The first version, dubbed Microsoft Internet Explorer, was installed as part of the Internet Jumpstart Kit in the Microsoft Plus! pack for Windows 95. The Internet Explorer team began with about six people in early development. Internet Explorer 1.5 was released several months later for Windows NT and added support for basic table rendering. By including it free of charge with their operating system, they did not have to pay royalties to Spyglass Inc, resulting in a lawsuit and a US$8 million settlement on January 22, 1997. Microsoft was sued by SyNet Inc. in 1996, for trademark infringement, claiming it owned the rights to the name "Internet Explorer". It ended with Microsoft paying $5 million to settle the lawsuit.

Internet Explorer 2

Internet Explorer 2 is the second major version of Internet Explorer, released on November 28, 1995, for Windows 95 and Windows NT, and on April 23, 1996, for Apple Macintosh and Windows 3.1.

Internet Explorer 3

Internet Explorer 3 is the third major version of Internet Explorer, released on August 13, 1996, for Microsoft Windows and on January 8, 1997, for Apple Mac OS.

Internet Explorer 4

Internet Explorer 4 is the fourth major version of Internet Explorer, released in September 1997 for Microsoft Windows, Mac OS, Solaris, and HP-UX. It was the first version of Internet Explorer to use the Trident web engine.

Internet Explorer 5

Internet Explorer 5 is the fifth major version of Internet Explorer, released on March 18, 1999, for Windows 3.1, Windows NT 3, Windows 95, Windows NT 4.0 SP3, Windows 98, Mac OS X (up to v5.2.3), Classic Mac OS (up to v5.1.7), Solaris and HP-UX (up to 5.01 SP1).

Internet Explorer 6

Internet Explorer 6 is the sixth major version of Internet Explorer, released on August 24, 2001, for Windows NT 4.0 SP6a, Windows 98, Windows 2000, Windows ME and as the default web browser for Windows XP and Windows Server 2003.

Internet Explorer 7

Internet Explorer 7 is the seventh major version of Internet Explorer, released on October 18, 2006, for Windows XP SP2, Windows Server 2003 SP1 and as the default web browser for Windows Vista, Windows Server 2008 and Windows Embedded POSReady 2009. IE7 introduces tabbed browsing.

Internet Explorer 8

Internet Explorer 8 is the eighth major version of Internet Explorer, released on March 19, 2009, for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008 and as the default web browser for Windows 7 (later default was Internet Explorer 11) and Windows Server 2008 R2.

Internet Explorer 9

Internet Explorer 9 is the ninth major version of Internet Explorer, released on March 14, 2011, for Windows 7, Windows Server 2008 R2, Windows Vista Service Pack 2 and Windows Server 2008 SP2 with the Platform Update.

Internet Explorer 10

… excerpt ends here. Continue reading the full article.

Illustrations

Logo for Internet Explorer 2

Worked examples

Example 1 — a first encounter with Internet Explorer

Start with the simplest possible case. Write down what Internet Explorer claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Internet Explorer before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Internet Explorer ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Internet Explorer

In research: Internet Explorer appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Internet Explorer in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Internet Explorer is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1995 software, Discontinued Microsoft software, FTP clients, so understanding it makes those chapters shorter.
In everyday life: Look for Internet Explorer outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Internet Explorer in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Internet Explorer means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Internet Explorer out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Internet Explorer in simple terms?

Why does Internet Explorer matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Internet Explorer?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Internet Explorer.