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, said Ramesh Iyer, mobile Internet device product manager at TI. "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.