Some of these building blocks are snippets of code that can be copied free from the internet, along with easy-to-learn programming frameworks (such as Ruby on Rails). Others are services for finding developers (eLance, oDesk), sharing code (GitHub) and testing usability (UserTesting.com). Yet others are “application programming interfaces” (APIs), digital plugs that are multiplying rapidly (see chart 1). They allow one service to use another, for instance voice calls (Twilio), maps (Google) and payments (PayPal). The most important are “platforms”—services that can host startups’ offerings (Amazon’s cloud computing), distribute them (Apple’s App Store) and market them (Facebook, Twitter). And then there is the internet, the mother of all platforms, which is now fast, universal and wireless.