Two external contributions have been accepted into Sisu.
Don Brown contributed patches to make Sisu more pluggable, while these exact patches weren't applied the concept was re-implemented using a strategy pattern
Gian Maria Romanato contributed a patch to make the Sisu extender code more re-usable:
There have also been a number of issues and feature requests reported by external users:
The sisu-user and sisu-dev mailing lists show a small but growing interest in the project, which hopefully will improve now that the refactored API is stabilizing. More tutorials and examples are sorely needed, and the wiki needs more details on how to contribute to the project. The forum is rarely used. Sisu is used in some form by the Maven, Hudson, and Nexus open source projects and members of those communities occasionally take part in Sisu discussions. Likewise the Sisu project lead takes an active interest in projects that adopt Sisu.