Google’s Android platform is gaining rapidly in the smartphone platform space. As per comScore which reports trends in the U.S. mobile phone industry, during October 2009 and January 2010 Google Android’s share of the smartphone subscriber base in the US rose by a whopping 4.3%.

Android continues to grow in popularity but the concerns being raised about Android’s approach and use of Java refuse to go away.

Appcelerator Titanium platform beta has been released with new mobile functionality that allows developers to use the Web capabilities they already have to develop rich applications for both iPhone and Android mobile devices.

Google I/O 2009 is being held on May 27 and 28 at the Moscone Center in San Francisco. One of the key themes of this year’s event is the unprecedented acceleration of the open web platform: Nearly half a billion people now use browsers that are rooted in open source technology, which have quintupled their processing power in less than a year. Now, the new functionality in HTML 5 — from graphics and location to local storage and background processing — is enabling developers to build uniquely powerful web applications.

The Android project has released an early-look software developer kit for Android 1.5. Developers can use the SDK to try out the new version of Android and also start creating mobile applications for the final Android 1.5 SDK release that is expected around the end of this month.

How you go about developing software for mobile devices depends primarily on which platform you intend to develop. While there are many large players competing in the the mobile platform market, there doesn’t seem to be an obvious winner.