Although I raised the issue of 1.4 compatibility, I'm personally in favor of moving to use 1.5 language features. I'd just like to keep the 1.4 issue in mind, which it seems we are addressing.
The 1.5 compatibility issue has to be addressed in two parts (unfortunately): use of language features (enums, annotations) and use of new APIs which may not have been backported. For the concurrent utilities, there is a backport (though I'm not sure it's being maintained) but for many other Java APIs, there is no backport. We ran into this on another 1.4-compatible FOSS project I work on where new methods were added to the XML parsing APIs in Java 5 and 6. I think one can solve that in part by seeking to maintain interoperability between River Vx and Jini 2.1. That way, people always have the option to host their existing code on Jini 2.1, and use parts of River under 1.5 where it makes sense for them. Patrick
