The Internet runs on standards. Without standards, we wouldn't have the Domain Name System (DNS) which resolves hostnames to Internet Protocol (IP) addresses, or the HyperText Transfer Protocol (HTTP) which served up this very web page. Even web service APIs, which can vary wildly depending on the back-end service, depend on standards like XML and JSON to make third-party development possible. And now, the W3C is jumping into the fray with a Working Draft for a general webapp Push API.
Location-sharing service Foursquare was down most of Monday, apparently due to a database issue. No Foursquare website or apps were available. And with the API also down, third party applications were helpless. Yet, it's a good reminder to developers to plan for downtime and to providers to have communications in place to let others know about your service's issues when they arise.