In Pictures: Amazon's Cloud feels the heat from Google, HP, Microsoft

Suddenly, IaaS is smoking hot

In the past few months, Google, HP, and Microsoft have announced they're getting into the IaaS game. Amazon now dominates the space, but can it fend off the invading tech giants? Smaller players like Rackspace -- now famous for its OpenStack "cloud operating system" -- and insurgents like Joyent are also intent on grabbing a piece of Amazon's pie.

In this slideshow, we've stuck with these five players, all of which allow customers to get up and running using a Web form. But other names bear watching, too, such as IBM and its SmartCloud Enterprise and the VMware-centric Terremark Enterprise Cloud, although both require you to engage with a rep rather than perform your own self-service startup.