Google's Android software platform for mobile phones is coming to life in Barcelona, with a number of chip manufacturers showing it running on prototype or proof-of-concept phones at the Mobile World Congress on Monday.

Freescale, Marvell, NEC Electronics, Qualcomm and Texas Instruments all had Android on show. Most of them expect to see Android phones based on their chips on the market in the second half of this year.

The hardware ranged from bulky development boards with daughter cards sticking out at unlikely angles to more compact devices small enough to slip into your pocket. All were built around chips containing processor cores designed by Arm, a British fabless semiconductor company.

One of the most polished prototypes is on the Texas Instruments stand -- although TI representatives insisted that it's just an example of how a finished product could look, as the company only makes chips, leaving the development of phones to its customers. "We don't do plastic," one said.

TI actually had Android running on two different devices. One was based on its OMAP850, a single-chip device containing an application processor for Android and a baseband processor for controlling the phone's radio interface. The other contained TI's OMAP3430 multimedia application processor, capable of decoding high-definition television signals at a resolution of 720p. It requires a separate baseband processor, and is designed for high-end multimedia phones.

Developing software for a new phone typically takes 14 to 18 months, mobile Internet device product manager at TI, Ramesh Iyer, said. "Android cuts that dramatically. It's a disruptor," he said.

Google is shaking the market in other ways, Iyer said. "Android is a single stack. You don't have to go looking for third-party solutions. Suddenly, they have defragmented the whole Linux ecosystem into one building block," he said.

Android is entering an already crowded market for mobile phone software: To see how crowded, you only had to look at the NEC stand, where four prototypes containing its Medity2 processor were packed onto a narrow table. One was running Symbian OS, one Windows Mobile, one Android on top of Wind River Linux -- and the last was running the same Wind River Linux, but with a different application layer based on software from Trolltech and Esmertec.

NEC staff expressed surprise at the level of interest in Android, saying they expected more attention for the completed phones based on the Medity2 at the next table. Manufactured for NTT DoCoMo, those phones contained the version of Linux promoted by the LiMo Foundation.

The two systems are not necessarily in competition, though. With Android's focus on the application layer and Limo's work on the middleware, the underlying services needed to link applications to the Linux kernel, the two can be complementary, NEC staff said.

Marvell took the prize for the most secretive Android demonstrations, refusing to allow photographs and declining even to say on which of its communications processors the software was running. The company showed a compact handset running the Android interface with a bare minimum of applications, and a more complete installation playing video and browsing the Web on a bulky development board. Shrinking that down to a pocket-sized device will not take long, staff said. In fact, they had one ready -- just not loaded with the Android software.

Android's Linux roots are likely to encourage the development of a wave of new handset applications, said Marvell's marketing director Vish Deshmane.

"You will see a lot more software to run on devices from people who want to exploit the commonality with desktop systems. It's going to be a boon for the 3G world because more applications means more data traffic, so operators will be happy," he said.

Over at Freescale Semiconductor, staff showed Google Maps zooming in on the center of Barcelona on a development board built around Freescale's i.MX31 processor. This processor is not intended for mobile phones at all, and is more at home in GPS (Global Positioning System) terminals or media players such as Toshiba's Gigabit and Microsoft's Zune.

Qualcomm's demonstration of its 7201 combined baseband and application processor sparkled, but did not exploit the chip's full potential. The spinning globe of Android's Global Time application turned smoothly even without the assistance of the 3D graphics hardware acceleration, for which the drivers are not yet ready, said Rob Woodford.

Android phones based on the chip will go on sale in the second half of this year, Woodford said.

The Mobile World Congress runs through Thursday at the Fira de Barcelona showground.