While there are clear slices of functionality across OpenStack projects and VMware products that compete in some ways, the general approach and philosophy of the two ecosystems are vastly different.
Seeing the differences in philosophy is more relevant than a side-by-side feature comparison. That said, understanding how to compare the technologies to one another helps clarify how they differ.
VMware was propelled forward by the adoption of virtualization in the enterprise. As virtualization continued to become increasingly commoditized, VMware gradually pushed up the stack; new value added features were layered around the hypervisor in pursuit of maintaining the market momentum, initiated by the “virtualization disruption.” Ultimately, VMware today is not about cloud, it is about datacenter automation. It is not about infrastructure as a service, it is about virtualization offerings focused at very specific enterprise pain points.
Infrastructure clouds in general and OpenStack in particular are not a byproduct of layering functionality around the hypervisor; neither were they originally targeted at the CIO or IT Manager pain points and, therefore, aren’t held back by having to cater to traditional enterprise workloads. OpenStack view of the world involves starting from scratch. It is the philosophy where one says “let us forget about all those existing enterprise applications and automate the infrastructure in a way that carries no legacy dependencies.”
IaaS involves a holistic approach to automating the entire infrastructure layer in a uniform way. It is not just about functionality layered around the hypervisor.