Let me start with a few disclaimers. By virtue of working in the IBM WebSphere Application Server team, I compete with SpringSource. I know, and like, several of the key people at SpringSource. I'm happy that their hard work paid of with such a large exit. While I compete with SpringSource, I'm excited that this acquisition will raise the bar for vendors that I care about, and ultimately, customers will benefit the most.
That said, although there has been a lot of analysis of VMware's acquisition of SpringSource, by in large it has accepted the vision of clouds and platform-as-a-service (PaaS) laid out in VMware's press release as a likely outcome. Let me try a different approach by discussing what VMware really bought.
VMware bought SpringSource because "Spring is everywhere"
Yes, but sadly for VMware, no. The Spring Framework is widely used in the enterprise Java market. From my own experience, many WebSphere customers use the Spring Framework on top of WebSphere. However, many WebSphere customers use the competing EJB open standard in place of the proprietary, but open source, Spring Framework. The most recent Eclipse user survey results found that of the 436 respondents building server-side applications, 47.5 percent were using the Spring Framework and 38.3 percent were using EJBs. Customers clearly exhibit a need for choice significantly higher than the proclamations of Spring's enterprise Java domination would suggest.
With such a high usage penetration, one could expect a significant revenue base for SpringSource. Yet, SpringSource is estimated to have driven $20 million in revenue, or maybe bookings, mainly from professional services. This is a very respectable base for a company with 150 employees. IDC, however, estimated the 2008 Application Server market at nearly $3.8 billion. While the Spring Framework is widely used, SpringSource has not been able to extract significant market share as a result.