A Slavic language related to Russian, Polish, Czech, and others, the continuum of dialects known today as "Bosnia/Croatian/Serbian" was the most widely spoken language in the former Yugoslavia, at its peak counting as many as 20 million speakers. Culturally, Yugoslavia's three regions, including eastern Serbia and Montenegro, central Bosnia and Hercegovina, and western Croatia were separated both religiously and linguistically from each other. As a result, the Serbian, Bosnian, and Croatian official languages as they exist today are based on distinct dialects and are written with two different alphabets, although because of their close similarity, some still consider the languages as a unit called "BCS."

(Description adapted from the UCLA Language Materials Project, (http://www.lmp.ucla.edu/Profile.aspx?LangID=189&menu=004).)

Bosnian and Croatian are typically written in the Latin script, and Serbian in the Cyrillic. Here is a text in Bosnian, Croatian, then Serbian:

Sva ljudska bića rađaju se slobodna i jednaka u dostojanstvu i pravima. Ona su obdarena razumom i sviješću i treba da jedno prema drugome postupaju u duhu bratstva.

Sva ljudska bića rađaju se slobodna i jednaka u dostojanstvu i pravima. Ona su obdarena razumom i sviješću i trebaju jedna prema drugima postupati u duhu bratstva.

Cвa људскa бићa рaђajу сe слoбoднa и jeднaкa у дoстojaнству и прaвимa. Oнa су oбдaрeнa рaзумoм и свeшћу и трeбa jeдни прeмa другимa дa пoступajу у духу брaтствa.

(Article 1 of the Universal Declaration of Human Rights, as cited by http://omniglot.com.)