This looks like it's taking the notion of "government as a platform" to
the next level.
My understanding is that the city is providing a new website called
CitySync which runs parallel to the main city website - though could
possibly replace the main website one day. This isn't just any
government website though, it's meant to be something residents can
really engage with and have a personalized account on. The real kicker
is that the city is providing an SDK for developers to build apps that
are integrated with the website (displayed through an iframe much like
facebook apps). They provide a sample app that lets you do a look-up and
analysis of schools: http://developer.pdxcitysync.org/sample-app/
I don't think CitySync is open source yet, but I believe the city plans
to open it at some point. It's built on Drupal 7.