Snapper is the founder of the Netherlands-America University League in California (NAUL-CAL). He organized eight international conferences on Dutch linguistics and literature, has served on the Editorial Boards of a number of publications, including the Publications of the American Association for Netherlandic Studies (PAANS), the Canadian Journal of Netherlandic Studies (CJNS) and De Nederlandse Taal. Among national and international offices he has held are the presidency of the American Association for Netherlandic Studies, membership on the executive board of the International Association for Netherlandics (IVN), and the chair of the Netherlands International Commission on Higher Education for Czechoslovakia, Hungary, and Rumania.