Sudan - long form Republic of Sudan - is in the northeastern Africa, and is the largest country on the African continent. It borders to (starting to the north and going clockwise) Egypt, the Red Sea, Eritrea, Ethiopia, Kenya, Uganda, Democratic Republic of the Congo, Central African Republic, Chad and Libya.
Map curtesy of Wikipedia, PD-USGov-CIA. Click for larger.
Sudan is home to about 42 million people of various ethnicities and beliefs, and while the standards of living differes across the country it is overall very much a developing country. The two major ethnic groups are arabs in the north and Black Sudanese in the south, but both these groups are split into hundres of smaller ethnic and tribal groups. Among them they speak aproximatly 133 languages. Or 142. The sources differ... at any rate Arabic adn English is the official languages, and at least one is spoken by all educated people (in cases where UNMOs ae talking to people with little formal education, translaters are empoyled).
The history of Sudan goes back to at least 3000 BC, with traces of habitation going back about 60000 years. The area was known to the ancient Egyptians as Kush, and was an independent state. By the 6th century AD the area was at least partly christian, with the Muslim Arabs gradually moving in from the 11th century and gradually becoming dominant. Northern Sudan was conqoured by the Ottoman Empire in 1820, and joined Egypt as a virtually independent part of that nation. The British Empire conqoured Sudan in 1899, and treated Sudan much as a British colony. In 1956 Sudan became indepentent once again, but quickly spiraled into a prolong civil war that continued in fits and starts until the Comprehensive Peace Agrement was signed in early 2005.
The signing of the CPA triggered the creation of UNMIS, whos mission it is to monitor the parties adherece to the CPA.
The future of Sudan is uncertain at this point - the South will have a referendum on indepenence in 2011, and the result of that will have a profond impact on the region no matter what the outcome is.