History lesson -
Yugoslavia means 'land of the south slavs'. It was an artificial construct of Tito out of the ashes of the slavic Ottoman and Hapsburg provinces after the first world war - five main ethnic groups, majority speaking Serbo-Croatian (which is effectively one language, Serbian, Bosnian and Croatian are written in different alphabets, but the spoken languages are only about as different as Australia and American English) then the Slovene and Macedonian speakers... There are also the smaller minorities of the Vojvodina Hungarians and the Kosovars, who are ethnically Albanian.
Slovenia, Croatia and Bosnia-Hercegovina broke away from Yugoslavia in about 1990, then Macedonia did the same not long after.
Serbia and Montenegro remained together under the title Yugoslavia until this year, they've now officially changed their name to 'Republic of Serbia and Montenegro'.
Expect the Serbs and Montenegrins to split soon as well. Within five years I'd be betting.