Web hosting provider XCalibre Communications (xcalibre.co.uk) hopes to loosen Amazon's grip on the market with its new service, FlexiScale (flexiscale.com), which offers pay-as-you-go on-demand hosting targeted at Web 2.0 startups.

Officially launched earlier this month at London's Future of Web Apps event, the company initially beta-tested FlexiScale for a couple of months before offering the service to paying customers.

"Right now [FlexiScale] is the only true European on-demand hosting solution available," says Tony Lucas, XCalibre Communications CEO. "It's the only one in the world that supports Windows and supports a lot of other things that make it easier for hosting, such as static IP address, permanent storage and integrated load balancing."

Whereas Amazon EC2/S3 and other similar services only offer support for Linux, FlexiScale offers full support for Windows. Other key features of FlexiScale include multi-level monitoring, load monitoring, automated elastic resource management and the ability to import any virtual server image.

Another important feature that distinguishes FlexiScale from Amazon EC2/S3 is the presence of service level agreements. FlexiScale assures its users by offering a guarantee of 99.95 percent uptime.

Other than FlexiScale and Amazon EC2/S3, there are currently only three other on-demand hosting companies available in the UK, including the US-based companies, Gogrid (gogrid.com) and MediaTemple (mediatemple.net).

The only other comparable European service comes from the Belgian-based Q-Layer (q-layer.com), which is aimed more at a corporate market than FlexiScale's target market of smaller startups that are looking to scale upwards. The company offers a fully virtual private data center on demand and in realtime. 

The lack of direct competition proves that there is a significant demand for on-demand hosting for new UK and European startups, making it the ideal time for FlexiScale to enter the market.

"To begin with, we've mainly been signing people with large media-related websites or Web applications," says Lucas. "The basic idea is that people's websites are extremely important to them and they're looking to have fairly large growth over the carrying period and they don't want to lower that with scalability issues."

So far, the service has received positive feedback from both prospective and newly-signed customers, says Lucas. And while he commends Amazon for its overall dedication to utility-based computing, Lucas says Amazon EC2/S3 falls short of practicality.

"Utility-based computing system is a lot friendlier to people who have to host websites than what Amazon's actually doing," says Lucas. "We have great respect for what Amazon is doing because they open people's minds to the utility computing idea, but it's not very easy to run a website off of Amazon's tool."