It all began when only a few were paying attention on September 2, 1969, when 20 people gathered in Kleinrock’s lab at the University of California, Los Angeles, to watch as two computers passed meaningless test data through a 15-foot gray cable, 40 years from now.

When they began tests 40 years ago on what would become the internet. Neither was social networking, for that matter, nor were most of the other easy-to-use applications that have drawn more than a billion people online.

The internet didn’t become a household word until the ’90s, though, after a British physicist, Tim Berners-Lee, invented the web, a subset of the internet that makes it easier to link resources across disparate locations. Meanwhile, service providers like America Online connected millions of people for the first time.

That early obscurity helped the Internet blossom, free from regulatory and commercial constraints that might discourage or even prohibit experimentation. The free flow of pornography led to innovations in Internet credit card payments, online video and other technologies used in the mainstream today.

Here is a quick journey of the internet from 1961 – 2008:

1969 | On September 2, two computers at University of California, Los Angeles, exchange meaningless data in first test of Arpanet, an experimental military network

1972 | Ray Tomlinson brings email to the network, choosing @ as a way to specify email addresses belonging to other systems

1973 | Arpanet gets first international nodes, in England and Norway

1974 | Vint Cerf and Bob Kahn develop communications technique called TCP, allowing multiple networks to understand one another, creating a true internet

1983 | Domain name system is proposed. Creation of suffixes such as ‘.com’, ‘.gov’ and ‘.edu’ comes a year later

1988 | One of the first internet worms, Morris, cripples thousands of computers

1990 | Tim Berners- Lee creates the World Wide Web while developing ways to control computers remotely

1993 | Marc Andreessen and colleagues at University of Illinois create Mosaic, the first web browser to combine graphics and text on a single page

1994 | Andreessen and others on the Mosaic team form a company to develop the first commercial web browser, Netscape. Two immigration lawyers introduce the world to spam, advertising their green card lottery services

1998 | Google forms out of a project that began in Stanford dorm rooms. US government delegates oversight of domain name policies to Internet Corporation for Assigned Names and Numbers, or ICANN

1999 | Napster popularizes music file-sharing and spawns successors that have permanently changed the recording industry

2000 | The dot-com boom of the 1990s becomes a bust as technology companies slide

2004 | Mark Zuckerberg starts Facebook at Harvard University

2005 | Launch of YouTube video-sharing site

2007 | Apple releases iPhone, introducing millions more to wireless internet access.

World internet population surpasses 250 million in 1999, 500 million in 2002, 1 billion in 2006 & 1.5 billion in 2008. Happy birthday, dear internet!