Below is an alphabetical list of vendors to get you started on your search for an IaaS provider.
Amazon AWS - EC2
Amazon is the granddaddy of IaaS providers. It was the first household brand name to provide such service. It is also the biggest provider. Originally, Amazon simply sold excess capacity from its own enormous infrastructure that it uses to power Amazon.com and all the associated services and products. However, its Amazon Web Services, or AWS, offering has quickly grown into a standalone business used both by numerous big name startups, and small users. Like many other IaaS providers, Amazon also offers numerous additional cloud services beyond straight infrastructure under the AWS banner. Amazon's Elastic Compute Cloud, or EC2, is the company's most direct IaaS product. Pricing is based on the size and type of instance created and the amount of time it runs.
AT&T Cloud Services
If Amazon and Google are the big names that leveraged their existing infrastructure to get to the cloud, and IBM, HP, and Microsoft are the big names that leveraged their existing expertise in server systems to get into the cloud, then AT&T is the provider that leveraged its existing worldwide network to jump into the cloud. AT&T Cloud Services' IaaS offering is called Synaptic Compute. Virtual machines start at $0.030 vCPU/HR, plus memory and storage. Image offerings are more limited than other providers and include just Red Hat Enterprise Linux 5 and Microsoft Windows Server 2008.
CenturyLink Cloud
Like AT&T, Century Link offers IaaS service based on its reputation as a provider of networks. What makes CenturyLink interesting is that unlike the other providers, its website has no table of costs. That's because CenturyLink offers custom-tailored instances instead of categorizing them as "high memory," "standard," "micro," or whatever. If you want to know what rolling out a server on CenturyLink IaaS will cost, you'll have to run its quote tool where a standard storage, Linux, 1 CPU, 1 GB memory, 1 GB storage will run you $18.40 per month. Bump it to Windows or Red Hat and pay $47.60 per month. Software licenses aren't cheap, apparently.
GoGrid
GoGrid, like RackSpace, is a company that only provides IaaS and its assorted add-ons. In other words, GoGrid doesn't do something else as its "main" business, like Amazon or Google. GoGrid provides the cloud. GoGrid offers CentOS, Debian, Ubuntu, and RedHat as well as both Windows Server 2008 and 2012 on your cloud server. There is an extra monthly licensing fee if you pick a Windows Server machine with SQL Server. They also offer a discount if you choose monthly billing, but then you can turn your server off to save money when it is not in use.
Google Cloud Platform - Compute Engine
Like Amazon, Google already had a massive world-wide infrastructure when it decided to get into the IaaS game. The IaaS part of Google's Cloud Platform is Google Compute Engine. Compute Engine offers numerous operating systems including Debian, CentOS, Red Hat Enterprise Linux, Windows Server and more. Google pricing offers different machine class types including: Standard, High CPU, High memory, and Small Machine. Cloud computing is one of the places where Google is playing catch-up to more entrenched competitors. The battle between Amazon, Microsoft, and Google leads to frequent pricing wars, and feature enhancements.
Hosting.com
Hosting.com positions itself as an IaaS provider for mid-size enterprises. The company allows customers to choose specific vCPU and memory amounts rather than offering a menu of services to choose from. While this allows the customer to make specific requests, it does mean dealing with a human and getting a quote before getting started (the horror!). Hosting.com is primarily focused on the U.S. market with six data centers across America.
HP Cloud
Like IBM, HP comes to the cloud from the world of Fortune 500 business deployments. Also, like IBM, HP will happily provide you the additional service and infrastructure to construct a hybrid cloud that coexists with an existing corporate network. The IaaS part of HP Cloud is the HP Helion Public Cloud. HP is a big contributor to the OpenStack community and the company integrates "key elements of OpenStack technology" in its offering. The best part of this, is that you can call your instance types "flavors" like they do in OpenStack. HP offers Standard and High Memory instance types (flavor types?), with Linux (CentOS, Debian, Fedora, Ubuntu) and Windows Server 2008 operating system images.
IBM Cloud - Softlayer
IBM's business model shifted long ago from just selling servers, to selling servers packaged with service and support to install and run that hardware. So, in one way, the move to selling virtual servers already installed and supported by IBM as IaaS was an easy move. On the other hand, like Microsoft IBM didn't start with a ready-made international network of servers and data centers, so the company bought Softlayer. IBM / Softlayer offers pure IaaS in form of bare metal servers, or virtual servers, with bare metal servers starting at $0.47/hr ($159/mo) versus just $0.04/hr or $28/mo for virtual servers. IBM also offers a fully managed IaaS, which it positions for use by corporate style IT departments.
Microsoft Azure
Unlike Amazon, Microsoft came to cloud computing as a way to expand its already entrenched server operating system business. Also, unlike Amazon, Microsoft had to build out its data center network specifically for Azure. When it came time to launch its Cloud OS platform, the company needed a place to serve it from, and no one can showcase a Microsoft operating system like Microsoft itself. However, contrary to what some people think, Microsoft's Azure IaaS offering is not Microsoft specific. Clients can provision Windows Servers, of course, but also any Linux VHD you care to upload, as well as a gallery of provided images such as Ubuntu and Oracle. Microsoft pricing is also based on the size and type of instance, as well as the type of operating system installed.
Rackspace Cloud
Rackspace just announced in early August that it is discontinuing its "pure" IaaS offering and transitioning to being a managed cloud provider. However, the only difference between Rackspace's managed infrastructure offering and raw IaaS is an additional fee based on the type and size of the instance. In other words, all of the hardware and virtual instances offered remain the same. In addition, existing Rackspace IaaS customers are grandfathered into previous pricing models. New customers will pay more than what the typical IaaS vendors whose offerings do not include service charge. For example, the company's Performance1-2 offering costs $0.065/hr for the "raw infrastructure" with an additional $0.01/hr charge for "managed infrastructure." In a way, this is simply an opportunity for Rackspace to bow out of the relentless pricing competition between Google, Microsoft and Amazon.
Toms It Pro
http://www.tomsitpro.com/articles/iaas-vendor-list,1-2228.html
