Mark Twain International School becomes an IB World School By Mark Twain IS 20 March 200620 March 2006 Mark Twain International School becomes an IB World School, authorized to offer the first of the challenging three-programme continuum of the International Baccalaureate, the Primary Years Programme, to its primary and pre-primary students. Previous IB Diploma Programme 26 November 2008 Next Mark Twain International School becomes the twin school of an IB World School, Rheintal International School 15 March 2009
