Gallery: Android's mobile competition

The consortium has come up with its own, Linux-based middleware platform, which LiMo has slowly and quietly started building into consumer-level handsets, such as the Motorola Motorokr EM30 (pictured above).

What are the pros?
Because LiMo's platform is essentially middleware, it aims to ensure compatibility across the industry, without taking away operators' ability to put their own, proprietary applications on top. This has led to great acceptance in the operator community, which is, in effect, the driving force behind LiMo.

Again, because LiMo is middleware, it can run on top of various operating systems, making it an attractive option for developers.

What are the cons?
As a rather slow-and-steady initiative, LiMo has not excited the public much. The greater public awareness of rivals like Android and the iPhone could steer developers in those directions.

Also, LiMo has yet to make an impact on the higher-end, more enterprise-friendly handset market. There have been rumblings that this might happen but, for now, LiMo is strictly geared towards phones in the consumer sector.

Next: Symbian.

Nokia has now bought up the bits of Symbian that it did not already own, and has joined forces with various manufacturers in a bid to combine Symbian with its derivates, UIQ and Series 60, and turn the whole resulting platform into open source. Pictured above is Nokia's E71, one of the most recent phones to use the Symbian-derived Series 60 platform.

What are the pros?
Symbian's massive popularity already makes it the first choice for developers who want to address the widest possible smartphone-user market. The open-source version will, therefore, garner great interest from an established developer community.

Nokia is also the biggest mobile-phone manufacturer in the world, and its leadership of the platform will automatically put the open-source Symbian into a wide variety of handsets.

What are the cons?
Symbian, in its present form, includes a lot of third-party, proprietary code that will need to be stripped out over the next year or two, before the open-source version of the platform makes its debut. Symbian is still working with third parties, and it remains unclear as to how the company will clear this hurdle and still come out with a recognizable, attractive platform.

Next: Maemo.

For the last three years or so, the Finnish manufacturer has been behind the Maemo Linux operating system, which it uses for its internet tablets such as the N810 (the WiMax edition of which is pictured above).

What are the pros?
Maemo has garnered a lot of interest from developers who are keen to address what many think will be an exploding market: that of the mobile internet device (MID). A lot of interesting applications have been created for the operating system, and N800-series devices have been the most visible MIDs to date.

Nokia also recently announced that the next generation of Maemo would, for the first time, support cellular connectivity. This will make it possible to create Maemo-toting MIDs that can use, for instance, HSDPA for data connectivity — until now they have only been able to use Wi-Fi.

What are the cons?
Developers have, thus far, been about the only people to buy Maemo-toting devices. The operating system remains, for now, fairly small fry in the mobile, open-source market.

Next: Openmoko.

What are the pros?
The completely open nature of the project has led to a dedicated following in the developer community, many of whom are also excited by the lack of domination by big-name companies.

Now into their second iteration in the FreeRunner, Openmoko handsets are starting to find some uses. A notable example is the NeoPwn project, which is turning the FreeRunner into a mobile, network-penetration tool.

The FreeRunner's touchscreen and GPS also mean the open-source community is getting to play around with and innovate on the current essentials for a mobile phone. The results of such experiments will feed back into the Linux kernel.

What are the cons?
Openmoko is, by the standards of the mobile-phone industry, an incredibly niche proposition. The FreeRunner, while an improvement on its predecessor, the Neo 1973, is still fairly clunky when compared to an iPhone.

The limited production runs on Openmoko handsets also mean they are relatively expensive and can be hard to obtain. While it may prove productive in the future, the Openmoko project is currently for hobbyists only.