When Twitter launches version 1.1 of its API sometime in the next few weeks, it plans to clamp down hard on developers who copy Twitter's own service. A blog post from Twitter's Michael Sippey cautioned, "Nearly eighteen months ago, we gave developers guidance that they should not build client apps that mimic or reproduce the mainstream Twitter consumer client experience. And to reiterate what I wrote in my last post, that guidance continues to apply today."
Sippey also said that third party developers will be required to use OAuth to authenticate all requests. In addition, developers will be limited to 60 calls per hour, per endpoint, instead of 350 calls per hour total, as is the case today. Finally, Sippey warned, "If you ship an application pre-installed without it being certified by Twitter, we reserve the right to revoke your application key."
The developer response to the changes was overwhelmingly negative. "Effectively, Twitter can decide your app is breaking a (potentially vague) rule at any time, or they can add a new rule that your app inadvertently breaks, and revoke your API access at any time," noted Instapaper's Marco Arment. "If I were in the Twitter-client business, I'd start working on another product."