Minority languages are languages spoken by a minority of a nation's inhabitants, usually the language native to a particular region or ethnic group. Often they are spoken by a majority within their linguistic domain - the group or area in which the language is spoken, but in some cases they are marginalized to the point that they are spoken only by a minority even in their own home.
In almost all cases, minority languages are faced with possible extinction as a result of any number of forces - governmental discouragement, lack of public education and official recognition for the language, the use of the majority language in public settings, and the association of the language with provincialism. Thus children never gain literacy or fluency in the language, or it is not taught to them at all, and only the elderly in many cases continue to use it.
This situation is extremely unfortunate, and even moreso in the case of many languages with a rich body of literature that will never be fully understood in the future. Such is the case with Occitan (Provençal), now spoken by perhaps ten percent of its region's inhabitants. The language is spoken in southern France and has a long history. It was spoken by the Troubadours during the Middle Ages, when its literature was spread across Europe. Later, however, the French government centered in Paris spread its then-obscure language, French, throughout the nation, and gradually displaced the language. Nowadays, practically no public education exists in the language and official recognition is nonexistent - a move typical of the French government, similar to its treatment of Basque, Breton, and Corsican. Only very recently has the French government begun to take grudging steps towards public education and broadcasting in minority languages.
Spain, in comparison, provides an excellent example of a government working to ensure the continued vitality of its entire heritage. Spain's regions are granted autonomy that includes the right to declare other languages co-official with Castilian (Spanish). Thus, Basque, Catalan, Galego, and Valencian all share official status in their respective regions. This of course doesn't guarantee the language's continued existence; economic and social factors may still limit the use of a language. But education and the availability of media in the language go a long way toward promoting its survival.
While the issue of minority language rights rarely is discussed in the context of human rights, it can be a major source for friction within a nation. Some governments prefer to promote cultural, and therefore linguistic, homogeneity rather than granting different groups the right to preserve their individual societies. Russia, for example, has a huge, varied collection of ethnicities within its borders, but even those within autonomous republics face discouragement in the use of minority language. The Russian government has long considered it more beneficial to encourage all of its people to abandon 'backwards' languages in order to join Russian society.
Even worse, minority languages can be repressed in a deliberate effort to suppress other cultures and their people. In Turkey, for example, it used to be illegal simply to speak Kurdish, and still today it is completely illegal to teach the language. Students have been arrested for circulating petitions calling for university classes in the language, and Turkey's government has worked diligently to erase the separate cultural identity of the Kurds and integrate them into the Turkish mainstream.
Language is integral to culture, and the death of a language means the end of a body of literature and of an important piece of a group's history and its very identity. Whether a language is deliberately repressed or passively given up by a group in order to integrate into larger society, it is a tragic loss to world culture. The international community needs to achieve greater understanding of the importance of the threat to minority languages in much of the world.
Update, as of August 5, 2002, Gritchka informs me that Turkey has just within the past couple of days liberalized the use and teaching of Kurdish. Yay!