From today however, Firefox OS will be available as a preview build which can be run on top of your existing Android OS without hacking it. Mozilla is releasing a “preview” build that runs within Android to give you a taste without any real commitment required. Sounds like a great idea but there are some risks attached to it. Since you will be running the Firefox OS on top of Android operating system, your smartphone may behave weirdly at times due to system errors. One of the errors noticed by Mozilla is that the Android back button may behave oddly at times. There is a good news for those who like bug hunting. Running your Firefox OS on top of Android OS gives you ample opportunities to go bug hunting and find some bugs of own. And if you grow tired of bug hunting or experimenting with the Firefox OS, you can always uninstall it like a normal Android App or APK. Seems simple! Ready to check it out? Head over to this Mozilla blog post and click the “visit Firefox OS 2.5 Developer Preview” link to grab the APK.