+1 for WIKIDATA
There are lots of useful WIKIDATA links and demos on this page: https://www.wikidata.org/wiki/User:Daniel_Mietchen/FSCI_2017...
There are lots of useful WIKIDATA links and demos on this page: https://www.wikidata.org/wiki/User:Daniel_Mietchen/FSCI_2017...
IMO the most interesting place right now for semantic web development is Wikidata. It's still pretty difficult for newcomers to contribute (as is the case for all Wikimedia projects) but at least it has many eyeballs and a very active community / ecosystem.