I tired installing "Maven Integration for Eclipse" plugin via Eclipse Marketplace on Eclipse 3.6.2 Java EE with the GEP plugin and Rational OSGI tooling installed. The Maven plugin installed fine but it failed to start. I tracked down the problem to a conflict in org.slf4j APIs. The GEP runtime plugins export the org.slf4j.* APIs with the given Geronimo version. For example, the GEP v3 runtime plugin exports org.slf4j.api with version 3. That confuses other plugins in Eclipse and causes the Maven plugin not to start.
I'm not sure 1) why we export the org.slf4j.* API out of GEP plugins in the first place and 2) if we need to export them why are we exporting them with the Geronimo version instead of the actual SLF4J version.