This may admittedly be of limited interest to those outside the DC area, but it's extremely interesting to me, so I'm afraid you'll just have to humor me for a paragraph or two. WMATA, our regional transit agency, has just launched a developer portal and API, and they've done a really nice job of it. People seem to love transit data -- after crime data it seems to be the municipal information people get most excited about (and I'd argue that it's much, much more useful than crime data) -- and I'm no exception. Playing with this stuff is a bit of a hobby of mine, and I've been following WMATA's gradual move toward openness for years. This is a big step forward for both the agency and its customers.

Bus data is still forthcoming, and I suspect that's where the real possibilities lie: the rail system is pretty easy to use; tech can pay bigger dividends when applied to the relative mysteries of the bus. Still, it's already clear that WMATA has made some smart decisions about implementation, defined reasonable terms of service, and generally seems to be moving in the right direction. When the API is considered alongside the already-released GTFS dataset, Metro's offerings match up fairly well (though not perfectly) with the ten open data principles that Sunlight has just published.

Now to see if I can't get a Graphserver instance running...