When Twitter bought Mixer Labs in December, 2009, it inherited the startup's then-recently launched GeoAPI, which offered a platform for building geo apps. The GeoAPI combined a places database of 16 million businesses with a reverse-geo-coder and support for geo-coded Tweets, Flickr photos, and even an iPhone SDK. Twitter kept the GeoAPI going after the acquisition—but that ends at the end of March. According to a developer who used to build his product on the GeoAPI, Twitter is shutting it down for outside developers. It is too much of a hassle to maintain, apparently. Twitter will still use it internally for its own apps. (Note that this GeoAPI is not the same as Twitter's more limited Geotagging API, which is still fully functional). So far no announcement on this. It's going in the deadpool. I've reached out to Twitter for a comment. Of course, Twitter has no obligation to keep maintaining the API. But the shutdown may be taken by developers as yet another sign that Twitter is not to be relied upon, and doesn't have their best interests at heart. Oh well, there still SimpleGeo and Factual. Update: Originally I reported that the GeoAPI was shut down yesterday but Twitter just got back to me and clarified that it will shut down on March 31. Twitter also says it already migrated most of the functionality over to the Twitter API, but the developer I spoke to decided to swap it out for a competing API because of the lack of support. If you are a geo developer, what do you think? Is Twitter API as good as the old GeoAPI or competing geo APIs? Enlighten us in comments. Here is the email Twitter sent to developers last December: Hi everyone, The core functionality and commonly used endpoints of GeoAPI.com have already been migrated to the Twitter API, and many are in use on twitter.com today. Our data shows that the features we have migrated to the Twitter API cover all but a handful of developers. With that, we want to let you know that the GeoAPI will be turned off on March 31, 2011. If you are still using the GeoAPI, we encourage you to move to the Twitter APIs at your earliest opportunity. To help you do this we have: 1. Matched GeoAPI place IDs with Twitter place IDs, allowing you to continue to query Twitter with the IDs you already know. 2. Documented the Twitter APIs on the Twitter Developer Resources site: http://dev.twitter.com/doc/geo If you have any questions about Geo in the Twitter API you can ask our Developer Advocates and Community through the Twitter Developer mailing list. You can join the mailing list through Google Groups: http://groups.google.com/group/twitter-development-talk/topics We thank you for having used GeoAPI.com to power places in your service.