Facebook F8 add a “Like” button to any piece of content on a website by the owner. This feature is now integrated within around 2.5 million websites worldwide, with 10,000 more being added daily. Additional news and announcements included: F8 2011 was held on September 22, 2011. Various things Facebook introduced at the conference included a new profile redesign named 'Timeline' that showed a history of user's activity on their profile, and a broader, more advanced version of the 'Open Graph' protocol. The F8 2011 event was mainly focused on introducing new products, transforming industries, building and growing social applications and product
S-train tunnel under the central station and the city centre. The high number of large cities in the Ruhr area promotes a polycentric network connecting all cities and suburbs. The "S-Bahn Rhein-Ruhr", as it is called, features few tunnels, and its routes are longer than those of other networks. The Ruhr S-Bahn is the only S-Bahn network to be run by more than one corporation in Germany, and the Salzburg S-Bahn holds a similar distinction in Austria. Most Swiss S-Bahn systems are multi-corporation networks, however. Most German S-Bahn networks have a unique ticket system, separated from the "Deutsche Bahn" rates, instead