March 1972 - The first basic email program is written.
The @ sign is chosen for its 'at' meaning.
1974 - Intel releases its first processor - the 8080.
1976 - Apple Computer is founded by Steve Jobs and Steve Wozniak.
Queen Elizabeth sends her first email.
1979 - Bob Metcalfe and others found 3Com (Computer Communication Compatibility).
1980 - Tim Berners-Lee writes a program called Enquire Within, the predecessor to the World Wide Web.
1981 - IBM announces its first Personal Computer (PC).
Microsoft creates DOS.
1983 - Cisco Systems founded.
November 1983 - The Domain Name System (DNS) is designed by Jon Postel, Paul Mockapetris, and Craig Partridge. The domain names .edu, .gov, .com, .mil, .org, .net, and .int are created.
24 January 1984 - Apple Computer introduces the first Macintosh computer.
15 March 1985 - Symbolic.com becomes the first registered domain name.
1987 - 25 million PCs are sold in the U.S.
1990 - ARPAnet ends and Tim Berners-Lee creates the World Wide Web.
1992 - The term "surfing the internet" is coined by Jean Armour Polly.
December 1994 - Microsoft licenses technology from Spyglass to create a web browser for Windows 95.
24 August 1995 - Windows 95 released.
1999 - AOL buys Netscape and, along with Microsoft, shares almost 100% of the browser market.
Oct 1999 - Shawn Fanning creates Napster, which opens up the possibilities of peer-to-peer file sharing and begins a copyright war in the music industry.
February 2000 - A large-scale denial of service attack is launched against major sites including Yahoo and eBay, sparking a security alert.
The 10-millionth domain name is registered.
2000 - Fixed wireless, high-speed internet technology is used instead of copper and fiber-optic lines placed in the ground.
Many of the 'dotcom' companies set up during the dotcom boom of the 1990s fold.
July 2001 - A judge rules that Napster must remain offline until it can prevent copyrighted material from being shared by its users.
The Code Red worm and Sircam virus attack hundreds of servers and email accounts, causing major security breaches.
January 2003 - The Internet celebrates its 'unofficial' 20th birthday.
2005 - YouTube launched.
2006 - There are an estimated 92 million websites in existence.
August 2006 - AOL announces that it will give the majority of its services away for free using funding from advertising income (services were previously charged on a monthly basis).
January 2007 - Microsoft launches its various consumer versions of Microsoft Vista.
February 2007 - Apple surpasses one billion iTunes downloads.
March 2007 - 1.1 billion people used the internet, according to Internet World Stats.
April 2007 - Search engine giant Google surpasses Microsoft as 'most valuable global brand' and also becomes the most visited website.
Christmas 2007 - BBC iPlayer launched.
2008 - Google celebrates it tenth birthday and launches the Google Chrome web browser.
Wikileaks is disabled.
Microsoft offers to buy Yahoo for $44.6 billion.
January 2009 - Actor Ashton Kutcher becomes the first Twitter member with more than a million followers.
October 2009 - Microsoft launches the Windows 7 operating system.
The internet reaches its 40th birthday.
By Vicky Woollaston