I was also looking for something similar to OSGi in the C++ world, ideally with a Qt-like API. I did not find something meeting the requirements for our projects and since I already had quite some experience in porting OSGi API to C++, I started working on the CTK Plugin Framework https://github.com/commontk/CTK/tree/master/Libs/PluginFramework (CTK is an international project involving major players in the field of medical imaging).
[quote author="smalltobi" date="1294739452"]
I have found a Qt based plugin framework: http://www.commontk.org
But this also doesn't seem to be very mature, yet and it is focused on medical applications.[/quote]
Although the context was originally medical applications, the plugin framework is not biased in any way towards certain types of applications. In fact, it is a very close imitation of the OSGi Life Cycle and Service Layer, with a Qt based API. As such, the API can be considered stable, although using applications just start to be developed.
Further, we also have implementations for some of the OSGi Compendium specifications. For example, EventAdmin (an event bus spec), ConfigAdmin (used to provide and manage configuration data for services), Logging, and MetaType implementations.
The plugin framework has no dependencies on QtGui and is licensed under Apache License 2.0.