I have been using the oracle VM, but I'll need to use a tablet soon at work. Therefore, I need to start experimenting with the android OS now. Is there a way to download the latest android OS and install it as a virtual machine in Ubuntu?
Yes Here is how:
and To install Virtualbox On Ubuntu Enter This In Terminal:
sudo apt-get install virtualbox
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You can also download Androdi SDK, where there are a emulator in which you also can run Andorid machines. http://developer.android.com/tools/workflow/index.html
And if you want to run ARM CPU, the software QEMU can also emulate a phone or tablet and run under Ubuntu. But I guess that Google uses QEMU to emulate their Android devices would be easier.
But this are an emulation of ARM CPU on your machine, that propbalbly doesn't use ARM CPU. Which mean it would be slower than running a Android in VirtualBox.