Mobile developers have a new playground to play in. Today, the Google-led Open Handset Alliance followed through on its promise to make its source code available for free as part of its Android Open Source Project

The first Android-based phone, the G1, was released earlier this month by T-Mobile and the Android software has been available to beta testers. Since the operating system is open source, the OHA is touting Android as the first truly open, full-featured mobile platform that lets anyone create a mobile device without restrictions.

However, the news comes at a time when mobile platforms are more open to developers than ever. Earlier today, Research in Motion announced it will launch a BlackBerry application storefront next March and is targeting the Web as a primary development focus. The handset maker also announced new tools today to kick-off its first-ever developer conference.

BlackBerry's storefront announcement follows the runaway success of Apple's App Store for the iPhone which has attracted thousands of developers and new applications. Unlike OHA, Apple (NASDAQ: AAPL) has tighter restrictions on what applications are approved for distribution. The OHA is further distinct in making the entire mobile "stack" or software layers necessary to build a mobile device, available as open source. The goal is to make hundreds or even thousands of Android-powered devices with, different configurations and features, available from a wide variety of manufacturers.

"It's a challenging time to be a mobile developer with so many platforms to choose from, RIM, Android, Apple, Windows Mobile and Symbian," analyst Maribel Lopez told InternetNews.com. "I think the reality is the industry has taken two steps forward and two steps back."

Lopez, principal analyst and founder of Lopez Research, said the new development platforms means more opportunity for customers to get cool and interesting new devices and applications, while developers get more chances to differentiate what they create.

"At the same time, you don't have the scale of the PC market, where you create, say, a Windows application that runs on over 80 percent of the hardware out there," she said. "It seems like there's a natural evolution going on as we progress from highly proprietary, locked-down platforms, to now where the developer can decide where best to spend their resources."

Andy Rubin, senior director of mobile platforms at Google (NASDAQ: GOOG), said the open source model allows greater access to ideas and innovations.

"An open sourced mobile platform that's constantly being improved upon by the community and is available for everyone to use speeds innovation, is an engine of economic opportunity and provides a better mobile experience for users," Rubin said in a statement.

Google said it expects an initial wave of Android applications to include location-based travel tools, games and social networking offerings available directly to consumers at low costs.

Choice or fragmentation?

Analyst Jack Gold said he expects the Android release to have a positive effect on the mobile marketplace. "It's going to enable a lot of creativity and that's a good thing," Gold, principal analyst and founder of J.Gold Associates, told InternetNews.com.

But Gold also warned that Android's open source foundation comes with risks. Companies can use Android as a starting point and add extensions. So, for example, a company might require that developers support additional features not in the standard Android code.

"In an open source environment, companies can do whatever they want to do, so imagine ten different companies going in ten different directions," Gold said.

"There are pros and cons to any new platform," he added. "With Android, we'll just have to see how well the community controls itself, managing new contributions to the code base and keeping a level of consistency."