gatespace.org

Sorry,
as the original author I stick to using Pax Logging all the time.

Mind you, Pax Logging also implements the OSGi Log Service, and should work out of the box, i.e. install the two bundles

pax-logging-api
pax-logging-service

into your framework. Off my head, I can't recall what the default Log4J Configuration is, but I think it is DEBUG.

The OSGi Config Admin service is needed to set the Log4J configuration beyond the default. Each entry in the Configuration instance (named "org.ops4j.pax.logging") corresponds directly to an entry in Log4J's configuration format (the Properties file variant).