Marathon has launched everRun VM, claiming it to be the world's first fault-tolerant software for server virtualisation.

According to the company, organisations will now be able to run high-value production applications over virtual machines, meaning that they would be able use virtualisation with a lot more applications.

The company has developed everRun VM to work in conjunction with Citrix XenServer. Marathon has replaced its own hypervisor with Citrix's. The process has been designed however, so that the Marathon software works seamlessly with Citrix's.

Although virtualisation has mainly been adopted by larger organisations, Marathon CEO Gary Phillips said that he hoped that everRun VM would be adopted by medium-sized businesses. "The implementation has been designed to make the process as simple as possible," he said. "It's a half an hour install; 15 minutes to install XenServer and 15 minutes to install Marathon. A company could manage it without an army of IT people."

He added that the software-only approach compared favourably with fault-tolerant hardware products such as Stratus - a company that recently put its own fault-tolerant drivers within VMware’s ESX Server. The advantage of software over hardware is that makes better use of existing equipment. "As soon as hardware becomes available, you can use it," said Phillips.

The company works with XenServer for now, said Phillips, but was looking at Microsoft's HyperV in beta and would look to release a product that supports that when the time was right.

Phillips said that everRun would offer users three levels of availability: the first level would be for system failover - eg customers would be able to handle CPU outage without data loss; level 2 would be aimed at the component level and level 3 would offer system-level fault tolerance. EverRUN VM is available now with Level 2; Level 1 and Level 3 add-ons will be available later in the year.

The US pricing is $2,000 (£990) per server per year, although that rises to $4,500 (£2,230) when bundled with Citrix XenServer. UK pricing is yet to be announced.