semantic web

hello,
 
I am working on geospatial semantic service matching.
I am wondering, the most popular choices for the software including open source in these area ?

Best Regards,

Res.Ass.Deniztan Ulutaş
Karadeniz Technical Universty
Department of Geodesy and Photogrammetry
Cartography division
Tel: 04623772781
05055893441
dulutas_21@hotmail.com