Hi Gordon (and whoever else is involved), What's the current status of metagraph / mpl_graph? I've been using msm::mpl_graph for error-checking/scheduling in a compile-time filter graph framework (similar to state machines, but focus is on data flow), and I'd certainly like to see more. As is, I've already implemented a topological sort based on the BFS which doesn't yield errors on cyclic graphs (which I'd be happy to contribute if you don't already have one), and I have some thoughts on improvement. I saw the BoostCon slides and the current state of the sandbox, and I was wondering if there's more code lurking out there somewhere, unchecked-in. Anyway, the single biggest flaw I see with the current BFS and DFS (and the BGL models they're based on) is that there is no way for the user to specify a termination condition in the base algorithm. It seems silly that an algorithm called "Search" can't end without traversing the whole connected component! Indeed, if there were simply an optional predicate determining whether a candidate vertex should be added to the stack/queue, I wouldn't have needed to write a separate algorithm for topo sort. The other thing is that not all of the listed visitor operations are called in the current implementations. Adding things like "initialize_vertex" and "non_tree_edge" to BFS is an easy fix. Thanks, Nick Kitten Software Engineer Center for Video Understanding Excellence ObjectVideo, Inc. http://www.objectvideo.com