Looking to spin up a virtual machine and get that project done in a hurry but not sure what your choices are in terms of cloud vendors?

Here is a listing (not a rating) of some of the top vendors and what they offer.

Amazon

Amazon Elastic Compute (EC2) is the dominant player. It offers several instance types in six groupings: Standard, Micro, High-Memory, High-CPU, Cluster Compute, and Cluster GPU. VM Import option allows you to import virtual machine images from your own environment at no additional charge. However, detailed monitoring is an extra charge but basic monitoring of EC2 instances is free. Amazon EC2 pricing requires no minimum fee and there's even a calculator to help you estimate your monthly bill and a detailed comparison page to help you choose between On-Demand, Reserved and Spot Instances pricing so you can make the best cost choice for your project. Specific Instances pricing is here. All told, EC2 is a full rent-a-data-center-service but it has crashed before so it is not infallible.

Rackspace

Rackspace Cloud Servers have gotten a lot of buzz lately around OpenStack, a joint Rackspace and NASA open-source cloud project. But there are a lot of moving parts thus the odds for something going wrong is higher. This is not necessarily a black eye for RackSpace as rival Amazon completely mishandled a crash in April underscoring that "stuff happens" even to the best of cloud vendors. Rackspace does offer very high customer service which is extremely helpful if something does go wrong. Pricing is based on server size with Linux-based servers being slightly cheaper than Windows. This site too offers a calculator to help you estimate costs in advance and a compare page that takes on Amazon EC2 head-on. Rackspace publicly claims superiority in a number of areas ranging from a greater selection of server sizes to third-party software support and admin level troubleshooting. Bandwidth is free between cloud servers but you have to upgrade your entire plan to upgrade storage. Pricing appears higher than Amazon but that may not translate to the final bill, especially if your project is small. You may get a better indication of pricing differences by running the calculators on all the cloud vendors and then compare the monthly estimates of each. All told, Rackspace is a strong company with an excellent reputation in support and delivery.

Joyent

Joyent is operating on a completely revamped infrastructure management platform called SmartDataCenter 6 which has granular analytics and added management, performance and security capabilities. Two free analytics packages, Joyent Cloud Analytics and New Relic, are included and they give users a good view into latency and other issues that some competing providers fail to reveal. Joyent uses SmartOS and KVM hardware virtualization. Pricing is based on server size with a minimal difference between Linux and Windows as is seen in the public cloud services field overall. Appliances, i.e. Percona/MYSQL, RIAK, Node.JS, and Zeus Load Balancer, are priced as an additional cost.

IBM

IBM got into the cloud game early albeit quietly. The IBM platform runs virtual machines in a variety of formats along with other IBM services. It tends to cater to more conservative enterprise developers rather than the bolder programming crowd. The pricing is a bit confusing and is detailed in a charging schedule. Anonline IBM SmartCloud pricing plan spells out a $3000 one-time fee for the Enterprise On-boarding Service Package and a $1000 one-time fee for a Virtual Private Network Service on unreserved virtual machine instances.

Cloudshare

Cloudshare offers a free trial period and a super simple browser-based process. No need to even enter credit card information to get started and play around to see if you like it. Multi-server, fully functional SharePoint farms come with fully-licensed, best practice SharePoint templates pre-installed. Pricing for the full enterprise product is not readily accessible online and requires a call to the sales department for a quote. Cloudshare ProPlus which is suitable for enterprise app use and designed for development, testing and collaboration of smaller teams, is priced online starting at $49 a month for unlimited hours (but subject to save and suspend after 60 minutes of no activity) and rising to well above $599 for the always-on option (no automatic save and suspend).

Terremark

Terremark's vCloud Express is VMware based and requires no minimum commitment. Live chat service is available from the landing page to help you get started or to figure out what you need for the project at hand. Chat follows you from page to page standing at the constant ready. While there is a full-blown Terremark enterprise option, vCloud is designed more for smaller businesses, individual departments, rapid prototyping, and developer coding and testing. Adding and deleting extra capacity is relatively simple although the vCloud pricing table isn't. Priority support is an additional $500 or 20% of your usage fees, whichever is greater in a given month. The good news is that you can enable priority support whenever you wish so it really isn't an expense unless and until you need it. Prebuilt server templates contain licensed Windows/SQL software for a fee based on the number of VPU servers you use.

Elastic Hosts

ElasticHosts also offers a free trial period, but for five days which is less than the 14 day free period offered by Cloudshare. Pricing is based on by month or by burst and an online calculator helps you calculate the cost in advance. You have a choice in UK and US-based data centers and you can pay in either U.S. dollars or British pounds. The service configures VMs like hardware and provides persistent storage, static IPs and a simple API. ElasticHosts also offers ElasticStack, a platformthat allows hosting providers and data centers to offer their own branded cloud services.

Dell and HP

IThe cloud space is getting very crowded and there are even more public cloud providers preparing to launch. Dell is launching its public cloud offering later this year. The company has strong experience in cloud computing with a wide array of products to help companies make the big move. Dell's public cloud offering teams the company with VMware and its vCloud Datacenter Services offering. Prices have not yet been announced but there is little doubt that Dell will be a serious contender worthy of full consideration as an option.

HP has also announced an upcoming public cloud service, which is now in beta but a public launch date has not been announced. HP's platform is based on the open-source OpenStack project which adds steam to that movement overall.

Notice that most of the public cloud players are companies you already know. That's the good news in that it lends familiarity to an otherwise tricky equation. The bad news is that there is lots of fine print to weed through and none of it tends to be straightforward. Make sure you understand all the legalities wrapped in the service level agreements (SLAs) to avoid problems later and run the monthly calculators offered on most of these sites to get a better feel for actual costs before you commit.