http://clep.collegeboard.org/
Developed by the College Board, the people behind AP and SAT, the College-Level Examination Program (CLEP) has been the most widely trusted credit-by-examination program for over 40 years, accepted by 2,900 colleges and universities and administered in over 1,700 test centers. http://about.collegeboard.org/
CLEP exams test mastery of college-level material acquired in a variety of ways — through general academic instructions, significant independent study or extracurricular work. CLEP exam-takers include adults just entering or returning to school, military service members and traditional college students.