Xwota is a GTK Client that connects to the WOTA Database (Who is On The Air - http://www.wotadb.org). Xwota is intended for amateur radio operators who want to make use of the WOTA database.
It can be used to find out who is on the air, the band and frequency they are operating on, and their location by country, state, county, grid, and latitude/longitude
It's very similar to a DX Cluster client, but it works with the WOTA database and contains more informations.
If you don't known what is the WOTA database, please read some infos at http://www.wotadb.org.