Gallery: 10 best open source mobiles

It pays to look back before looking forward and Trolltech's Greenphone - which debuted in 2006 - was an important step in the open source mobile movement as it claimed to be the first fully reprogrammable Linux phone.

Despite being a handset that was only offered to developers and with only around 1,000 devices made before it was discontinued, Trolltech's dream of a flourishing Linux ecosystem has surely been successful - albeit not necessarily in the way it originally envisaged.

Three years on from the advent of Greenphone and mobile Linux is in rude health, thanks in large part to Google's Android OS.

Trolltech is now known as Qt Development Frameworks and concentrates its efforts on its Qt graphical toolkit software.

Credit: David Meyer/ZDNet UK

Taiwanese mobile maker HTC used to be all but married to Microsoft's Windows Mobile OS but the arrival of Google Android has seen a seismic shift with the company planting a foot squarely in the open source camp.

The Hero is its latest Android offering - a slick touchscreen handset running Android but also skinned with HTC's own UI, called Sense - showing how the platform is changing.

Credit: HTC

The second Android device made by HTC was called the Magic - similar to the Hero in that it's also a touchscreen offering but this device has only a vanilla version of the Android OS without HTC's Sense UI on top.

Credit: HTC

The first smartphone to be released running Google's Android OS was the G1 - made by HTC and exclusive to T-Mobile.

Like the HTC Magic, the device comes with the Android UI. It differs from the Hero and Magic by having a slide-to-reveal physical Qwerty keyboard as well as a touchscreen.

Credit: Natasha Lomas/silicon.com

Another mobile maker to join the Android crew is Samsung - pictured here is its Galaxy i7500 with the now familiar vanilla Android homescreen.

Credit: Samsung

Symbian has traditionally been Nokia's OS of choice but with an open source version still in the pipeline, the Mighty Finn has yet to make a big impact in the open source smartphone world.

However it does have a finger in another open source pie with a Linux-based OS called Maemo, which it's used on its line of internet tablets. The latest of which - the N900 (pictured above) - comes with wi-fi and cellular connectivity, making it a smartphone in all but name.

Credit: Nokia

Much less visible outside Japan are smartphones running the LiMo Foundation's Linux-based open source OS but there's no shortage of such devices, especially from operator NTT DoCoMo. The Foundation says there are now more than 40 LiMo handset models out in the wild.??Pictured here is a waterproof gadget from the NTT DoCoMo Style series which promises easy enjoyment of mobile TV in the bath...

Credit: NTT DoCoMo

Mobile maker Motorola is involved in two open source movements - it has several devices running the LiMo platform but pictured here is its first Android device, known as the Dext in the UK.

Beyond Android, the device is interesting as it has a customizable homescreen allowing the device to automatically sync with a user's social networking services and other feeds - a service called Motoblur. There's also cloud back-up so any data kept on the phone is also stored remotely.

Credit: Motorola

Samsung also has its own open source offering: this device, the H1, is based on the LiMo platform. The handset comes with Vodafone's 360 service (pictured here) preloaded - a similar offering to Motoblur, with social updates fed automatically to the device and data backed up on the fly.

Credit: Vodafone

Another open source handset of note is the Neo Freerunner from Openmoko, a smartphone for users with more than the average requirements for customizing their device. The hardware is so open it's even possible to run Google's Android on it.

Credit: Openmoko