As promised in the Top 10 Technologies post, here are more details regarding JCR and the way we use it in projects.
In the other post, I have written about the requirements we usually encounter in projects when it comes to dealing with content in web applications. Not only functional requirements but also non-functional requirements such as "content is stored at different places and must be made available at a single point" were most probably the reasons for Day Software (located in Switzerland) to bring that extra layer to life and started leading the JSR-170.
Instead of rebuilding all that from scratch, Cambridge Technology Partners has chosen many times to propose and implement a JSR-170 based solution.
Being in contact with Day directly, we carefully track the evolution of JCR, currently mainly in the JSR-283 area where the JCR 2.0 standard is about to reach its final state (currently in Public Review Ballot phase).
Since JSR-170 started, it is a hot topic in different places:
a) at conferences like JavaOne in 2006,
b) on the feature lists of product vendors (JSR-170 compliance),
c) used internally in open source products like for managing business rules, for universal resource storage and for SOA governance management and last but not least
d) CTP had many projects in the Enterprise Content Management area where we used JSR-170 bridges (e.g. "SPI to JSR-170 bridge" in the BEA WebLogic Portal where SPI is the BEA custom content interface to their Virtual Content Repository in the portal), we used JCR products directly in projects (mostly Alfresco but also Jackrabbit which is the reference implementation both being good enough for small companies, Vamosa as content migration tool where customers wanted to automate content migration from a legacy content repository to a JCR (and yes, vice-versa also :-). To make the list complete, on projects we never had the chance to use Day's Content Repository Extreme (CRX), eXo JCR (part of the eXo platform), Mirage or Jeceira (part of the Jackrabbit alternative Magnolia).
As said earlier, the official successor JSR-283 is on its way and addresses enhancements in the areas of federation, remoting, client/server protocol mappings and extensions to content modeling capabilities just to name a few. I'm sure we'll compile an extra post on this topic... so check back later.