RPath on Monday released version 5 of its rBuilder product for building virtual appliances to run under Linux and ease the number of steps needed to create a workload for Amazon's EC2 and other cloud computing environments.

RPath was established by CTO Erik Troan and a small group of former Red Hat staffers in Raleigh, N.C. Troan was the originator of the packaging concept for adding to and modifying parts of the Linux operating system. With the headers and other package information, a developer could tell which Linux updates and patches had been included in his build of the operating system.

RBuilder combines an application with an optimized version of its operating system and converts them into a set of virtual files. RBuilder has been used as a free online tool at the rPath site to build many Amazon Machine Images, the virtual file formats that run in Amazon's EC2 cloud, which uses the Xen open source hypervisor.

RBuilder is now available as an enterprise tool for building virtual appliances to run directly on a server or in different virtual machine environments. Its output files can be designated to work with VMware's ESX Server hypervisor, Citrix Systems' XenServer or Microsoft's Hyper-V. RPath comes with an open source repository, Conary, which stores the virtual appliance, along with its configuration information and definitions.

RBuilder analyzes an application to understand what parts of the operating system it depends on and what middleware it needs to run with it. That may include scripts written in Perl, Python, PHP, or some other dynamic language. Under version 5, it "dramatically reduces the complexity and number of steps needed to get to a ready-to-run system," VP of marketing Jake Sorofman said in an interview.

With cloud computing, "we're seeing a significant surge of interest in this new approach for delivering applications," Troan said in a statement accompanying the version 5 announcement.

RBuilder appliances also run in clouds provided by commercial supplier BlueLock and the academic research cloud Nimbus, formerly known as Globus Work Space, as well as EC2, said Brett Adam, rPath's VP of engineering.

The rBuilder tool has built-in version control through the open source tool Conary. After mapping an application's dependencies, the configuration information of how it works with its version of Linux is stored in Conary, and any changes to the configuration become a new version. By tracking all changes, application users can go back to one that works, if an application fault is encountered.

Version 5 includes a management console through which to build, launch, and store applications. With its option to produce a pre-configured application in a virtual appliance, console users can deploy the application to a variety of enterprise environments, from a bare server to a private cloud, said Adam.

"We think organizations should focus on applications, not infrastructure. Version 5 treats applications more like services that can be stored, called up, and moved around, making it a better fit with service-oriented architectures," he added.

RBuilder in its enterprise version is priced on the basis of the number of application instances it has created and that are running. It's available for $35,000 in its initial year of operation and scales upward in price as the number of running instances increases. It's available for free trial download for creating up to 20 application packages.

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