Foursquare has just announced that they are switching from Google Maps to OpenStreetMap.

This is a pretty significant new development for Google Maps as one more major player is discarding them for an open source offering.

Foursquare spoke about the move:

Starting today, we’re embracing the OpenStreetMap movement, so all the maps you see when you go to foursquare.com will look a tiny bit different (we think the new ones are really pretty). Other than slightly different colors and buttons, though, foursquare is still the same site you know and love.

We’ve been using the Google Maps API since the early days of foursquare. In the last six months, though, we’ve seen an increasing number of companies migrating to other options. So, during our January hackathon, one of our intrepid engineers wondered what the world would look like if we made our own maps. To do that, he used data from OpenStreetMap. (It’s a crowd-sourced global atlas, and it’s kind of amazing! It’s like Wikipedia for geography.) We love the idea of open data, and were happy to try it out.

Google Maps recently started charging for access to their API for heavy users. Foursquare did say that this was one of the reasons for the switch but it makes sense for them to work on their own mapping technology looking at the future.

Foursquare is working with MapBox for their own maps.

Update: As of now, on my installation it seems to be still using Google Maps.