A number of vendors have got together and published the SCA specification together with a bunch of folks working together at Apache to create Tuscany,
an Apache licensed implementation of SCA. I really like the SCA
specification; its simple, clean and elegant - its a great POJO based
programming model for application developers to use. I like the use of
scopes and the conversational services support too.
I particularly like how SCA POJOs can work with SDO or work with JAXB 2
marshalling. I'd like to see support for SCA services which work
directly with XML Source or JBI's NormalizedMessage too :). I'm also
glad it looks like the @Property and @Reference annotations are
optional for public setters too - and that the use of @Reference
defaults to a mandatory reference (the common case).
We're looking forward to integrating SCA support into ServiceMix (hopefully by reusing some Tuscany code :) to complement the Spring, JSR181, JAX-WS, JCA and SAAJ programming models.
Incidentally ServiceMix and ActiveMQ are moving to Apache too; which coupled with Tuscany, Geronimo and Synapse, its looking like the SOA stack of the future is going to be created at Apache. These are exciting times!