Swedish startup Xcerion on Tuesday launched the public beta-test of iCloud, a virtual desktop aimed at consumers and mobile workers, which it hopes to develop into an application marketplace comparable to Apple's App Store.
For end users, iCloud offers a web-based desktop available from any internet-connected PC and offering a set of productivity, developer, media and communications applications.
Microsoft and Google are the best-known providers of web-accessible applications, with projects such as Google Apps. Unlike their efforts, iCloud attempts to recreate the look and feel of a full-fledged operating system running in a browser, including a desktop, application icons, widgets and applications running simultaneously in separate windows. (Images of iCloud are available on ZDNet UK's sister site, CNET News.com.)
iCloud applications are written in Ajax, like Google Apps, but iCloud applications run entirely in a 2MB virtual machine loaded into the user's browser.
The virtual machine offers an abstraction layer, which is designed to insulate the applications from the underlying browser technology, simplify development and improve performance, Xcerion chief executive Daniel Arthursson told ZDNet UK on Thursday.
One drawback to this approach is that the virtual machine must be ported to new browsers or platforms for them to support iCloud, said Arthursson. Currently only Internet Explorer is supported, but Xcerion is planning support for browsers such as Firefox.
The company also plans to port the virtual machine (VM) to non-PC platforms such as mobile phones. Once the VM has been ported, individual apps will not need to also be ported, said Arthursson.
"As soon as we have ported the VM into another browser, or outside the browser, for instance to C++ for smartphones, iCloud can work on those devices," Arthursson said.
The applications run locally, meaning that, once loaded, they can continue to operate offline, as long as the browser remains open.
The same application can run simultaneously on different users' iCloud desktops, allowing a document to be edited by multiple users at once, with modifications passed along to the different users by a transaction co-ordinator in the datacentre, Arthursson added.
Performance has been Xcerion's main stumbling block. In a demonstration to CNET News.com last year, the iCloud environment proved slow to load, and a planned public beta launch at the end of 2008 was delayed until now, while the company worked on performance issues.
Xcerion said it began working with Akamai in March, giving it access to 25,000 servers worldwide, and making it more likely that the user will be working with a server geographically close to them.
"We have rewritten a lot of the code that communicates from the virtual machine to the servers, and have been able to remove a lot of bottlenecks," said Arthursson. "We are continuing to learn a lot about how to run a global internet service."
Xcerion said it plans to turn iCloud into a marketplace where developers can offer applications for a fee, or on a free, advertising-supported basis. The company plans to charge 25 percent of developers' application revenues, compared to Apple's 30 percent cut on its App Store.
The free version of iCloud gives users 3GB of storage space and a WebDAV backup feature, enabling file synchronisation across different systems. This means, for instance, that a user could synchronise files between an iCloud desktop and a physical desktop.
Xcerion was founded in 2001 and is funded by Northzone Ventures, a Swedish venture-capital firm, as well as Lou Perazzoli, one of Windows NT's original architects; John Connors, a partner at Ignition Partners; and Terry Drayton, founder and former chief executive of HomeGrocer.com.
The system is available from iCloud.com in English, Chinese, Russian, Spanish, Portuguese, German, Swedish and Filipino.
Other so-called "cloud operating system" efforts include Laszlo Webtop and the now-defunct YouOS, while companies such as Salesforce.com offer comparable web-based application environments.