Work started on that, present in my github tree (https://github.com/charles-dyfis-net/basex/commits/java_util_logging).
Good news, I'll look at that soon.
FYI -- I rather strongly disagree with building our own indirection layer to dynamically switch between logging libraries, when at least two such layers already exist on the market [...]
True. All this is related to a more general question: do we want to allow dependencies to other libraries in the BaseX core, or do we want the core to stay monolithic/as is? As we are accumulating more and more projects that are embedded only if they are available in the classpath (igo, tagsoup, jline, xml-resolver, ...), our current approach may get too limiting at some stage. On the other hand, people frequently appreciate the fact that the BaseX core still works out-of-the-box without any dependencies.
If we decide to abandon our ascetic attitude, we may still have to decide which libraries won't introduce too much redundancy in terms of functionality; on the other hand, it will be much easier to embed other projects into our core product. And, last but not least, we could merge the "basex" and "basex-api" projects, as those are tightly connected anyway.
We're keeping you updated, Christian