Terracotta and Ehcache, two promising open source companies, expect to register a slight tremor on the Richter scale today when the industry, particularly the Java contingent, finds out that Terracotta bought Ehcache last week.

The move, after Ehcache reportedly rejected three other offers, should have Oracle’s Coherence people gritting their teeth and Red Hat’s JBoss unit looking for a box of tissues while VMware purrs like a kitten since it’s buying SpringSource, which has an existing relationship with both Ehcache and Terracotta.

Meanwhile, IBM should have its usual schizophrenic multiple reactions.

The marriage is supposed to create the market leader in caching and Java application scalability, a company with the world’s largest caching footprint offering enterprise-class Java performance, scalability and availability solutions.

See, Ehcache, despite being a one-man show, is the most widely used Java caching solution, effectively a de facto standard with enterprise production deployments reportedly numbering in the hundreds of thousands, including most of the Global 1000.

It also ships as a component in other Java products including Hibernate ORM, the Spring Framework, Alfresco CMS and the Liferay portal.