By 2010, 90% of software as a service (SaaS) providers will have some open-source component in their technology infrastructure stacks (that is, operating system, application server and database) to reduce software acquisition expenses, according to Gartner. 

User communities are expanding around application-platform-as-a-service providers and will leverage open-source practices for sharing software applications.
"As the community of SaaS users increases, along with the emergence of associated application-platform-as-a-service providers' open-source-type practices, application exchange will continue to grow," says Robert DeSisto, vice-president and distinguished analyst at Gartner.
"Community capabilities, such as voting and validation of those useful applications vs. ones that are not, will help self-police these emerging communities. The more SaaS vendors use open source in the technology stack, the lower their software acquisition cost becomes. Users, however, should not expect cost savings to be passed on to them in the form of lower prices. Vendors may choose to improve profitability or increase R&D efforts with their savings."
From the user perspective, open-source-like applications will constitute at least 30 per cent of an application as a service provider's ecosystem of available applications built on the provider's native platform. This is the infancy of application-as-a-service SaaS platforms and their corresponding ecosystems. The combination of platforms and ecosystems will foster communities that will leverage open-source practices.
"Consider leveraging communities where the underlying SaaS provider enables the community through an application platform as a service," says DeSisto. "The success of a provider's platform will be highly dependent on the success of the community; therefore, the provider of the platform is likely to take actions to support ecosystem success. It is also important that IT organisations take an active role in governing the use of any open-source SaaS offering, specifically to ensure that the company using the offering is properly indemnified from any downstream patent infringement actions from the open-source elements that the SaaS providers are using."