SpringSource wrote in a FAQ on the acquisition that it would keep RabbitMQ, which is based on the open standard Advanced Message Queuing Protocol (AMQP), open source. The company also said it would continue to fully support the RabbitMQ developer community.

RabbitMQ has a track record of use as the backbone of messaging servers for cloud computing environments. Its integration with SpringSource will likely make it a compelling messaging option for developers building private and public cloud applications on Spring Java. As it is built on AMQP, RabbitMQ can be used for application and service messaging as well as communication with front end systems like end user applications.

Spring users most often use JMS for messaging, said Rod Johnson, general manager of VMware SpringSource, when we spoke earlier.

“But we are now seeing greater interest in AMQP, specifically Rabbit, than in the past,” said Johnson. “Spring will continue to integrate with a wide variety of JMS providers and what we will be doing is trying to make sure that Rabbit is a very attractive option for the spring community.”

Johnson said AMQP is arguably better suited to federation than JMS. Many cloud environments are multi-language and multi-platform. Where this is the case, having something tied to Java, like JMS, can be more problematic. For instance, Johnson said if you use a product with a JMS binding, you may get stuck using its proprietary bindings on other platforms. On the other hand, AMQP, as a standard, is available in multiple languages and favors interoperability.

Alexis Richardson, CEO of Rabbit Technologies, gave an example of someone wanting to deploy a cloud service that would be used by all the different mobile phone platforms. How a developer push data to those mobile devices?

“They can either build a whole lot of different clients and somehow wire them up to JMS,” said Richardson, “Or they can use a protocol, which is supported independent of the platform by individual platform providers.”

When going with a protocol, AMQP joins HTTP, XMTP and HTML5 in the developer’s arsenal – with the added benefits around things like queuing, data delivery and content routing.

“So really its about combining the benefits of something like HTTP with something like JMS, which is specific to Java,” said Richardson, “But in an open manor suitable for cloud deployments.”

This week, VMware made its Tomcat-based SpringSource tc Server 2.0 available for download. The release represents a continuing integration of SpringSource’s application development platform into VMware’s virtualization business, following its acquisition of SpringSource last year. As part of the release, the company introduced the tc Server Spring Edition, which is supported on VMware’s virtualization products.

Ovum analyst Tony Baer told me today that SpringSource/VMware integration is a work in progress. He pointed out VMware’s aggressive promotion for getting tc Server into its go-to-market channel. Until May 8 2010, any customer order fulfilled with vSphere, vCenter, View or ThinApp products will come with two free, perpetual, production-use tc Server licenses and 60 days of evaluation support.

“What’s most interesting is that VMware is ready to unleash its go-to-market channel on SpringSource,” said Baer. “The barometer of VMware’s success with SpringSource will be the degree to which it can ramp up the channel to go, in essence, higher up the software stack with tc Server.”

It was a bold move VMware made in acquiring SpringSource and thus expanding its business from operations alone to include application development. However well the cultures of these two companies blend, they have certainly carved out a niche in enterprise Java virtualization with the light-weight Spring Framework.

Spring is quite a bit leaner than the standard Java EE, which many say makes it better suited to virtual environments like private and public clouds. The lighter the application server instance, the more of them you can pack into one physical server. And indeed, VMware has been pushing Spring for private clouds more and more.

It seems that SpringSource is working also to capture as much of the mindshare around enterprise Tomcat as possible. Last month SpringSource launched TomcatExpert.com, where it offers a library of Tomcat resources and hopes to build an active community. This site is less a forum and more a knowledge base where contributors can post tips, stories, presentations and questions for experts.

Whether or not VMware SpringSource ever becomes the go-to vendor for enterprise Tomcat app servers, the company sure is positioning itself to make an impact in the Java cloud platform space.