- Eucalyptus – “EUCALYPTUS – Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems – is an open-source software infrastructure for implementing “cloud computing” on clusters. The current interface to EUCALYPTUS is compatible with Amazon’s EC2 interface, but the infrastructure is designed to support multiple client-side interfaces.” If VMware is perhaps working on responding to EC2, this could be thought of as EC2’s response to VMware ESX, in a way – although it’s coming from UCSB, not Amazon. Notable: This is a product that layers on top of a Rocks cluster installation. (Seen at High Scalability.)