Finding reliable data is often one of the hardest parts of large visualisation projects, so news that “computational knowledge engine” Wolfram Alpha are to open up their datasets through an API is a welcome development. Wolfram Alpha disappeared from the news as it became clear they’re not a rival to Google (in either’s current form at least) but offering an open API should bring a new range of mashups and visualisations by other developers tapping into the range of structured data available, such as astronomy, weather and finance.