Last year, I developed Semantic Tasks, an extension for Semantic MediaWiki that sends e-mails depending on semantic properties of pages (see http://www.mediawiki.org/wiki/Extension:SemanticTasks for more detail)
It was used very efficiently for a SMW-based task tracking system at Creative Commons.
Unfortunately, I received some feedback recently telling me
it doesn't do its job anymore with the current MediaWiki and SMW
releases. I'm sorry for that and I won't find time to fix it unless I
have personal interest in using it, which may happen, but not in a near future. I'm sure fixing it wouldn't require so much work.
This is why I want to put it up for adoption. The code is located in the MediaWiki SVN. Organizations of any kind could find an interest in using it and improving it.
I will follow this thread for any additional information.