What is the fine-grained topic of the following text: Silicon Graphics Incorporated (SGI), the Californian based server manufacturer, has filed for bankruptcy protection and agreed to sell its assets to Rackable Systems Inc.
Two very different projects have closed this week: Microsoft's commercial Encarta, and after just 14 months, the free search engine Wikia Search. Only return the topic.
Silicon Graphics Incorporated's bankruptcy and sale, and the closure of Microsoft's Encarta and Wikia Search.