RightScale, the Santa Barbara cloud management start-up, has gone multi-cloud.

Besides Amazon’s EC2, where its users reportedly have hundreds of thousands of instances running, RightScale widgetry now works on GoGrid and UK-based FlexiScale clouds too.

It’s also working with Rackspace Hosting to support its Mosso and CloudFS infrastructure.

RightScale CEO Michael Crandell expects the company to be the first in the industry to offer an integrated management dashboard where applications can be deployed once and managed trans-clouds.

Deploying apps on a cloud is notoriously time-consuming; RightScale promises cost-effective rapid deployment and best practices.

It currently offers built-in redundancy, fault tolerance and the geographical distribution of resources. Users can scale to demand.

FlexiScale is the only UK-based cloud computing provider and offers infrastructure on demand with a 99.99% SLA. Each customer gets his own virtual disk so that data is segregated and he can do his own low level encryption, while virtual network traffic is also segregated to deliver added security. FlexiScale offers permanent on-demand storage and was the first cloud provider to support Windows.

GoGrid offers hosted cloud computing infrastructure so system administrators, developers and IT professionals can create, deploy, and control load balanced cloud servers and complex hosted virtual server networks. It also delivers portal-controlled servers for Windows 2003 and 2008 (both 32-bit and 64-bit), multiple Linux operating systems and supports application environments like Ruby on Rails.