In a break with tradition and a long-awaited nod to transparency, Apple today gave iPhone and iPad application developers their first access to the guidelines it uses when evaluating App Store submissions. The company also relaxed its restrictions on the tools that developers can use to create apps for its devices.

The guidelines turn out to be a surprisingly fun read, full of attitude.

"We view Apps different than books or songs, which we do not curate," reads the introduction. "If you want to criticize a religion, write a book. If you want to describe sex, write a book or a song, or create a medical app. It can get complicated, but we have decided to not allow certain kinds of content in the App Store." [Read the full document here (PDF) via Engadget.]

But the actual guidelines won't be much of a surprise to longtime iPhone app developers, based on what they've been able to deduce from the response to their past app submissions.

Ubermind, a digital agency that makes iPhone, iPad, and Android apps, has been making submissions since the App Store launched, and maintaining its own list of guidelines based on its experience. What Apple released today was "consistent with a lot of the materials that we already have compiled," said Shehryar Khan, the company's chief executive.

At the same time, he said, the newfound transparency should prove more helpful to people just starting to develop iPhone apps.

Seattle-area iPhone app developer Michael Schneider of Hive Brain Inc. called the publication of the guidelines "a smart move by Apple, and something they probably should have done a long time ago."

"They clearly have had an internal list of things that would get an app rejected, and it helps developer relations for everyone to know what they are," Schneider said via email. "From a technical standpoint, I don't think they changed much about their approval process. They still have the right to reject apps for things that aren't on their list if they feel it is appropriate. The big difference is the additional transparency in what their existing criteria are."

Apple's new development flexibility was welcomed by companies including Google, which said in a blog post that the changes "ensure that Apple’s developers have the choice of a variety of advertising solutions," including its own. The news was also seen as good news for Adobe's development platform.

Although the changes will make it easier to port applications from other mobile platforms, Ubermind's Khan said the company won't be seizing that opportunity. Different mobile platforms have different characteristics that will still make it valuable to use the development tools native to that particular platform. When a new version of the iPhone comes out, he said, Apple's tools will be the first to take advantage of any new hardware features.

"In our experience," he said, "the best way to innovate on the iPhone platform and build apps that have the best user interface is to use the tools that Apple itself provides."