There are a number of upper ontologies that have appeared over the years: SUMO,BFO,Cyc,DOLCE. Barry Smith claimed recently the need to have one in order to preserve consistency for the semantic Web. Which one is the most popular ? Which one do you prefer and why ?
Taking a look at prefix.cc, it seems that the most popular on the Web among the ones you mention is Cyc (based on usage of the namespace). Would Yago qualify as an upper ontology in your view? It seems very popular according to prefix.cc (I'm not sure though how prefix.cc defines popularity). Anyway, it's utterly impossible and there is no need to preserve consistency for the Semantic Web (unless I don't understand what Barry Smith means by that). In my opinion, the utility of an upper level ontology is:
- in providing readily available terms for most things without the need to craft a custom domain ontology;
- in allowing other ontologies to be mapped to it instead of aligning n ontologies one-to-one.
I prefer RDF/S - it's a nice tight ontology that leaves your definitions a lot of room to grow.
Another nice, broad upper ontology is "gist" by the folks at SemanticArts: http://semanticarts.com/gist
UMBEL is also quite comprehensive.