Belgium is a European nation-state bordering France, Netherlands, Luxembourg, and Germany. Belgium is home to a linguistically diverse, though small, Hip Hop community. Dutch is spoken in the Flemish north, while French is spoken in the Walloon south. Benny B. (Wikipedia) popularized Hip Hop in Belgium. He was considered too commercial by some, so they reacted with a hardcore underground sound.

De Puta Madre (Myspace page, Wikipedia) is a group formed in the early 1990s from Schaerbeek and rap in French and Spanish. Here's their bio in English.

Starflam (Wikipedia) is a French-speaking group from Liège and Brussels that formed in the early 1990s. Here's a bio in English for the group. Souterrain is a French-speacking collective including Rival, Pitcho, CNN199, Lady-N, Defi J, and Ekolu. Here are their bios in French.

Frithop is a term coined by the group ABN and denotes rap in local Dutch dialects. However, ABN, from Mechelen, actually rap in standard Dutch. Here's their bio in English. 't Hof van Commerce (Myspace page, Wikipedia) is a group from Izegem, who rap in regional Dutch, specifically West Flemmish. Here is their bio in English. Krapoel In Axe (K.I.A.), who rap in the dialect of Aarschot, were the most commercially successful Frithop group. Here's their bio.

other artists:

Ultime Team is a Belgian group. Here's a review of their album, Umoja.

Akro (Myspace page) from the group Starflam.

Da Familia (Myspace page) is from Liège.

Libertas Gentes (Myspace page) is another group from Belgium.

Jean Christophe Matata, raised in Burundi, resides in Bruxelles.

other sites:

Wikipedia's entry on Belgian Hip Hop.

Here's an article: A Belgian, Ugandan Hip-Hop Collaboration.