In short, life for third-party Twitter app developers just got harder, and Twitter is clamping down on some of the key differentiations those apps currently offer today. And if life for the developer behind your favorite third-party Twitter app gets harder, that may mean that the developer in question eventually stops supporting or updating the app.

Though Twitters increasing crackdown on third party apps isnt surprising, its certainly disappointing. Twitters modern success, of course, was driven largely by the third-party app ecosystem that built up around the service in its early days. in 2010, turning that app into its official iPhone app. And the third-party app to use the word tweet to describe a post, the first to use a bird icon to represent the service, the first native Mac client, the first app to use a character countdown while you composed your tweet, the first to support replies and conversations, and the first native client on the iPhone.

Twitter wont say publicly what percentage of its users are relying on third-party apps today. One study concluded that are posted using third-party apps, but it didnt look at the relative Twitter influence of the folks posting those tweets. Put another way: Its quite possible that Twitters most popular users, the ones with the largest followings and reach, rely on third-party clients more than newcomers who tweet often but without reaching anyone. As you embrace Twitter more and use the service more regularly, you may become increasingly aware of and interested in third-party apps.

At least, thats how its been for years. While third-party apps drove a tremendous amount of Twitters early adoption and growth, its clear that Twitter now regrets the current state of affairs, and would prefer to own the tweeting experience outright. Thats understandable from a business perspective, but painful for developers and users who bought in to a different Twitter years ago.

As someone who tests a lot of apps, Im especially bummed, becauseas John Gruber wrote. Ive awarded s highest, five-mouse rating to at least two Twitter apps, and I cant think of a single other app category thats generated such a slew of greatness.