I released version 0.1.2 of SPQR this morning; it is available from gemcutter (as an installable gem package) or from fedorahosted.org (as source). This version contains many enhancements and fixes when compared to the versions described my previous SPQR posts. I've noticed that people are still installing older versions of SPQR and would like to encourage everyone who's interested in using SPQR to adopt the most recent version.
The 0.1.x series and the 0.0.x series are not API-compatible, but the incompatibility is for a good reason: it enables SPQR to expose normal Ruby methods (that is, those that don't use keyword arguments). To see what I mean, compare the "Hello, world" example from v0.1.2 with its counterpart in v0.0.4. (The former is also embedded below, but you might have to click through to the post to see it if you're reading this in a syndication feed.)
Here are some other enhancements to the code since the last time I mentioned SPQR:
Many fixes and enhancements to SPQR/Rhubarb (simple object-graph persistence) integration; most glue methods are now automatically generated at runtime.
Improved code generation from XML QMF schema files, including support for generating classes that are both exposed over QMF (with SPQR) and persistent (with Rhubarb).
A stable and mostly-repeatable test suite. (I hope to write up the process of developing unit tests for QMF agents at some point in the near future.)
Enhancements to the app skeleton, which can now specify the broker that manages the QMF bus.
Many fixes and stability enhancements, most of which have come out of my experience with a substantial SPQR/Rhubarb application I'm developing.
The full list is here. Enjoy, and please don't hesitate to write with questions.