About Facebook
Founded in February 2004, Facebook is a social utility that helps people communicate more efficiently with their friends, family and coworkers. The company develops technologies that facilitate the sharing of information through the social graph, the digital mapping of people's real-world social connections. Anyone can sign up for Facebook and interact with the people they know in a trusted environment.

Product
Facebook’s simplified navigation gives users easy access to core site functions and applications. Profile, Friends, Networks and Inbox – pages core to the user experience on Facebook – have a prominent place at the top of the user’s profile page. Facebook applications – Photos, Notes, Groups, Events and Posted items – are displayed on the left side bar, along with any third-party applications a user has added to their account.

Technology
Facebook is the second most-trafficked PHP site in the world, and one of the largest MySQL installations anywhere, running thousands of databases. Facebook has built a lightweight but powerful multi-language RPC framework that allows the company to seamlessly and easily tie together subsystems written in any language, running on any platform. The company is the largest user in the world of memcached, an open-source caching system, and has created a custom-built search engine serving millions of queries a day, completely distributed and entirely in-memory, with real-time updates.