the 1980s, as well as many other computer networks of both academic and commercial use such as USENET, Fidonet, and the Bulletin Board System. By 1989 the Internet and the networks linked to it were a global system with extensive transoceanic satellite links and nodes in most developed countries. Based on earlier work, from 1980 onwards Tim Berners Lee formalized the concept of the World Wide Web by 1989. Television viewing became commonplace in the Third World, with the number of TV sets in China and India increasing by 15 and 10 times respectively. Video game consoles released in this decade included the continuing popularity of Atari 2600, Intellivision, Vectrex, Colecovision, SG-1000, NES/Famicom, Sega Master System, PC Engine/TurboGrafx-16, Mega Drive/Genesis and Game Boy. Super Mario Bros. and Tetris were the decade's two best selling and most popular video games. 1980's Atari VCS port of Space Invaders was the first killer app. Pac-Man was the decade's highest grossing arcade game. Home computers in that decade include the Commodore 64, VIC-20, the Apple II series, the Atari 8-bit family, Atari ST, Amiga, ZX Spectrum and MSX. Apple Macintosh, Microsoft Windows and IBM PC compatible were also introduced in that decade and helped popularize personal computers. During the 1980s, the world population grew from 4.4 to 5.3 billion people. There were approximately 1.33 billion births and 480 million deaths. Politics and wars Terrorist attacks The most notable terrorist attacks of the decade include: Bologna massacre in Italy on August 2, 1980, three members of the neo-fascist group Nuclei Armati Rivoluzionari detonate a time bomb at Bologna Central Station, killing 85 people. El Mozote massacre in El Salvador on December 11, 1981, against civilians, committed by government forces supported by the United States during their anti-guerrilla campaign against Marxist–Leninist rebels. The Rome and Vienna airport attacks took place on December 27, 1985, against the Israeli El Al airline. The attack was done by militants loyal to Abu Nidal, backed by the government of Libya. The 1983 Beirut barracks bombing – during the Lebanese Civil War two truck bombs struck separate buildings housing United States and French military forces killing 299 American and French servicemen. The organization Islamic Jihad claimed responsibility for the bombing. Air India Flight 182 was destroyed on June 23, 1985, by Sikh-Canadian militants. It was the biggest mass murder involving Canadians in Canada's history. On December 21, 1988, Pan Am Flight