While most of the focus on collaboration applications running in the cloud has focused on the battle between Google and Microsoft, IBM has quietly been stealing a march on both.

IBM today rolled out a key missing component in its collaboration suite in the cloud with a new Lotus Live iNotes offering that provides Web mail, calendaring and contact management as a service for $3 a month per user.

The new service, which is based on technology that IBM acquired when it purchased a company called Out Blaze, complements existing Lotus Live services for collaboration and social networking.

IBM’s stance on cloud services echoes Microsoft’s software plus services mantra in that IBM believes most customers will opt to extend their on-premise investments in software to the cloud, rather than replace everything will a cloud computing service. That’s an especially compelling model for all the developers that have built applications on top of the Lotus Notes platform.

Nevertheless, there are large numbers of corporations that don’t see the value in managing their own messaging platform. Instead, they would rather redeploy limited IT resources to support more mission-critical applications, while relying on cloud computing services for basic messaging services.

IBM officials expect to be able to make Lotus.Live more customizable as time goes on. For example, users should be able to share parts of an application with others without having to expose the entire application.

IBM’s primary pitch in the space is that it can deliver a true business-grade collaboration experience that is not only more secure, but also significantly more reliable than competing services. Longer term, however, IT organizations should expect to see various cloud computing service providers coming together at the application level to set standards that would make it easier to federate services across disparate cloud computing platforms.