After Tito's death, tension between the various peoples grew, and since 1991, Slovenia, Croatia, Bosnia and Herzegovina and Macedonia all gained their independence. Nowadays the only remaining republics are Serbia and Montenegro , with the status of Kosovo still uncertain. Because there were large ethnic minorities within the various countries (Serbian regions in Croatia and Bosnia, Croatian in Bosnia, Albanian in Serbia and Macedonia, Hungarian in Serbia), this led to some often bloody civil wars (Croatia, Bosnia?, Kosovo War).
Country code (Top level domain): YU
During most of the 20th century, a number of states in the Balkan was unified under the name of the Socialist Federal Republic of Yugoslavia. All of them but Serbia and Montenegro left the federation in the 1990s. The United Nations, and many other states (including the United States) refused to recognize the remaining confederation of Serbia and Montenegro as the continuation of the Socialist Federal Republic of Yugoslavia, although they accepted it as constituting a state. This situation is now resolved, with the admission of the Federal Republic of Yugoslavia to the United Nations in 2000 (or was it 2001?).
From the CIA World Factbook 2000. Not Wikified.