WSO2 provides free and open source SOA middleware components (ESB, App Server, etc.) on a customizable, modular framework called Carbon. Last year, WSO2 started offering its components as cloud images, but they were not cloud native. Stratos provides these components natively in the cloud, which means when you log into Stratos and immediately provision your own domain with the services you want via the Cloud Manager. The components are completely self-service, elastically scalable, and comprehensively metered and monitored.
If your organization needs an ESB, for example, they can instantly provision one on the multi-tenant architecture and let the metering and monitoring tell you what resources are being used by each tenant. Having these services be cloud native saves memory because (unlike with the images) you don't need to allocate new VMs for each service, which cost about half a GB on each server used.
WSO2 co-founder and CTO Paul Fremantle blogged about [http://pzf.fremantle.org/2010/06/wso2-stratos-platform-as-service-for.html] Stratos, saying that unlike Force.com or Google App Engine, you have the option to run applications internally. Stratos offers an enterprise architecture with governance, business process, integration, portals, identity management and mashups. It also supports the common Enterprise Programming Model (Java, JAX-WS, BPEL, XSLT, XPath, WSDL, etc.). Only Tibco Silver provides similar offerings.
WSO2 believes in the open source business model, and takes it very seriously. One problem that Fremantle is seeing in today's cloud/software platforms is lock-in:
"Software vendors love lock-in - and Cloud vendors love it even more. So if you code to Google App Engine, you are tied into Google's identity model, Google's Bigtable, etc. If you code to force.com or vmForce - you are tied to force's infrastructure services. If you code to Tibco Silver, you are tied to Tibco. WSO2 fights this in three ways:
No code lock-in: we use standards-based coding (WAR, JAX-WS, POJO) and Stratos is 100% Apache License Open Source.
No model lock-in: we use standards-based services:
No hosting lock-in: you can take you apps and data from our public PaaS and re-deploy internally or on your own virtual private cloud anytime you like."
- Identity is based on OpenID, OAuth, XACML, WS-Trust
- Registry is based on AtomPub and REST
- Business Process is based on BPEL, etc
Stratos can run on the web, Amazon VPC, or private clouds based on Ubuntu Enterprise Cloud, Eucalyptus, and others. Support for VMware's vSphere will be coming soon. You can test-drive WSO2 Stratos on the web right now.