At Twitter, a Web Site Is Revamped and Simplified - NYTimes.com

Definitely a tumultuous Twitterverse transition time

But as Twitter has matured, it has angered many of those developers by building similar tools itself or acquiring the start-ups that built the tools, limiting opportunities for competing app developers. Last spring, for example, it bought Atebits, which made a Twitter iPhone app called Tweetie, and turned it into the official Twitter for iPhone app.

Other start-ups worry that if Twitter builds its own tools, they will go out of business. Indeed, mobile Twitter users now reach Twitter through the company’s own iPhone and BlackBerry apps more than through any others, according to the company.

“We’ve made it pretty clear that we are going to create the best experiences we can with all our clients,” Mr. Williams said. “We made it clear to developers that it’s great for everyone if we make it as good as possible, because that will create more successful Twitter users.”

At Twitter, a Web Site Is Revamped and Simplified - NYTimes.com