“Cool vendors” reports have always been among my favorites, and Gartner’s “Cool Vendors in Cloud Computing Management and Professional Services, 2009” paper published last week has a great overview of 5 select start-ups in the cloud computing space with Gartner’s take on their strengths and weaknesses.

This time they looked at:

• Appirio – which provide professional services and integration solutions based on salesforce.com for various web 2.0 services including Google Apps, Facebook, and Amazon. They are doing relatively well and their 2,000 customers include Japan Post Office, Qualcomm, Genentech, and Author.
• CohesiveFT – a cross-platform virtual appliance packaging solution for VMware, Xen, Parallels, and Amazon EC2. They also have a product called VPN-Cubed which allows companies to set up secure networking between their servers across the clouds.
• Hyperic – application and infrastructure monitoring solution for Amazon EC2 (I wrote about them in my notes from Cloud Computing Expo last year.)
• RightScale – cross-cloud automation engine and a set of application templates.
• Ylastic – browser-based Amazon-management interface for mobile phones and other devices.

As you might guess more or less for all of them the challenges listed include growing competition, promising but still relatively small revenue opportunities, Amazon’s ever improving native management functionality, and the big vendors should they decide to enter the space.

One other useful datapoint in the report is the licensing and pricing information for the vendors as well as their quick history info.
You can find the report here.