were also released during the decade. With the advent of the Web 2.0, dynamic technology became widely accessible, and by the mid-2000s, PHP and MySQL became (with Apache and nginx) the backbone of many sites, making programming knowledge unnecessary to publish to the web. Blogs, portals, and wikis become common electronic dissemination methods for professionals, amateurs, and businesses to conduct knowledge management typified by success of the online encyclopedia Wikipedia which launched on January 15, 2001, grew rapidly and became the largest and most popular general reference work on the Internet as well as the best known wiki in the world and the largest encyclopedia in the world. Open-source software, such as the Linux operating system, the Mozilla Firefox web browser and VLC media player, gain ground. Internet commerce became standard for reservations; stock trading; promotion of music, arts, literature, and film; shopping; and other activities. During this decade certain websites and search engines became prominent worldwide as transmitters of goods, services and information. Some of the most popular and successful online sites or search engines of the 2000s included Google, Yahoo!, Wikipedia, Amazon, eBay, MySpace, Facebook, Twitter, and YouTube. More and more businesses began providing paperless services, clients accessing bills and bank statements directly through a web interface. In 2007, the fast food chain McDonald's announced the introduction of free high speed wireless internet access at most of its 1,200 restaurants by the end of the year in a move which will make it the UK's biggest provider of such a service. Popular websites Google, YouTube, Ask.com and Wikipedia emerged as popular websites, becoming the 2nd, 3rd, 7th and 9th most popular websites by the end of the decade respectively. Amazon overtook eBay as the most-visited e-commerce site in 2008. AOL significantly declined in popularity throughout the decade, falling from being the most popular website to no longer being within the top 10. Excite and Lycos fell outside the top 10, and MSN fell from the second to sixth most popular site, though it quadrupled its monthly visits (going from 325 to 1.2 billion monthly visits). Yahoo maintained relatively stable popularity, remaining the most popular website for most of the decade. Electronics GPS (Global Positioning System) became very popular especially in the tracking of items or people, and the use in cars (see Automotive navigation systems). Games that utilized the system, such as geocaching, emerged and became popular. Green