Some time ago, Mozilla, the company behind the popular Firefox browser, introduced something called Firefox OS. Pretty much exactly what you think it is, Firefox OS is a lightweight operating system designed to get people online, and little else. The idea behind the project is that low, low cost devices can be produced running the OS in emerging markets and help get people online with little hassle. You could think of it as a mobile equivalent of Chrome OS, but unlike Chrome OS you need very specific hardware to try it out. Chromebooks are one thing, but Chrome OS can be shoehorned on to most laptops fairly easily. Now, Mozilla is offering up a simple way for Android users to do the same.
The Firefox OS 2.5 Developer Preview is available for the curious to download and install on any Android device using the free APK. You just need to download it and install it as you would any other Android app you've found online. Considering Mozilla is a well-established name, this should be perfectly safe to do, but as this is a Developer Preview not everything is going to run all that smoothly or indeed work at all. The way the preview works on your Android device is similar to how an aftermarket launcher would work, when you press the home button you can use it as you would another homescreen app, but it does have its own web browser, settings app and more. It's an interesting experience to say the least, and a lot more different from Android than we were expecting. Being able to experience and try out new things on an Android device is what it's all about though, so it's nice that we can finally experience an official version of Firefox OS without having to hack our devices open or anything like that.
This Developer Preview of Firefox OS 2.5 is completely free to download and use, but it won't be for everyone and it doesn't quite work as smoothly as it would on dedicated hardware. Nevertheless, a free app that is good fun to play around with and see where Mozilla are headed with Firefox OS.