Hm, I know I've brought it up before. In relation to OpenCyc: ConceptNet doesn't have CycL or any sort of logical predicates -- the assumption is that you are

Hm, I know I've brought it up before. In relation to OpenCyc: ConceptNet doesn't have CycL or any sort of logical predicates -- the assumption is that you are just doing fuzzy machine learning over ConceptNet. I'm pretty sure you need the rest of Cyc to do anything interesting with CycL, though. ConceptNet takes advantage of linked open data when it can, so it does contain attempted translations of the facts in OpenCyc. Compared to the Google Knowledge Graph: well, you can't really use the Knowledge Graph without being at Google, or making a research agreement with them, right? But from what I've seen of it, and of its predecessor Freebase, I think it focuses a lot on named entities: particularly things you can look up on Wikipedia or things you can buy. Which is fine information. I'd say it's a different segment of linked data than "what words mean", which is ConceptNet's focus. So maybe think of it as more like a bigger WordNet than a smaller Knowledge Graph. How to add domain-specific concepts to ConceptNet: the unsatisfying answer is that you can get the code for ConceptNet and alter the build process to include new data sources (try it on the 5.5 branch if you attempt this). And the startuppy sellout answer is that doing this automatically is one of the things my company Luminoso is for (http://www.luminoso.com http://www.luminoso.com). Thanks for asking, and I'll try to clarify this kind of stuff when I deploy the new site.