Avalon is a component framework. My first encounter with it happened in 2000, we used it in our own J2EE framework. Also, Cocoon Project uses it. There are powerfull concepts implemented in Avalon, such as SoC and IoC.
Recently, I got involved in a project, which is supposed to use Merlin container. The matter is that Avalon is a framework, and there are several implementations of it, such as Merlin and Fortress. So, I wanted to find out what's going with these containers. It seems that the state of Avalon is troubling according to Sylvain, and I share his worries. Several committers are not happy, and some of them left a project. It was decided to take Merlin as a single reference implementation, but I'm not sure that all deveopers will support it. The mailing-lists were hot, and concerns don't seem to be resolved. Honestly, I can't predict what's going to happen with Avalon now.