CIO — When putting your systems in the cloud, a few options are available depending on exactly what you want to put there and for how long. Although each vendor offers essentially the same service—a place to move your computing efforts away from your own infrastructure—they break down the pricing in a number of ways. Make sure you take into account your specific needs to find which cloud suits your company best.

Amazon

Elastic Compute Cloud (EC2) provides an environment to run computing resources while keeping the control over the data in the user's hands and emphasizing pay per use. As users' requirements change, EC2 allows for easy scaling of capacity. Pricing is per terabyte per month, which decreases a few cents as the data amount increases. Users build their own Amazon Virtual image to include customizable features such as an operating system, starting and ending usage dates, security and network access controls, APIs or other management tools and the number of locations.

Google

App Engine allows you to build your own virtual application to run Web applications on Google's servers in either Java or Python environments. Resources used by the applications, such as bandwidth and storage, are free for up to 500MB of data plus the CPU and bandwidth needed to serve more than five million page views a month. Once users surpass the free limits, prices are per gigabyte only for the extra resources used. Usage limits can be set so you never use more than what you are willing to pay for. Features include dynamic Web serving, automatic scaling and load balancing, storage sorting, APIs for authenticating users and more.

Skytap

Virtual Lab supplies users with a ready-made platform on which to operate their applications and virtual machines without needing to build virtual machine images. As such, it gives users instant gratification for moving servers to the cloud, especially those requiring temporary usage of computing. Users are able to customize features of the platform, such as access and assets, through a provided management tool. The services target development and testing environments. Subscriptions for limited use of the self-service lab management application start at $500 per month. For additional fees based on usage of storage and data transfers, users can select an unlimited capacity option.

VMware

vSphere 4 is a virtualization operating system providing the capability to move physical infrastructures into the cloud. By moving all physical data centers, companies not only save money on computing and energy-related costs but also have one silo for storage and resource management. Pricing starts at $166 per processor or $995 for three physical systems and varies depending on the edition purchased. Depending on the size of the company, different versions are available and include different features, such as vMotion management tools, VMsafe security APIs and data recovery, among others.