Czechoslovak Genealogical Society International collect and publish genealogical, cultural, and historical research materials and information concerning all ethnic groups that comprised the nation of Czechoslovakia as it was formed in 1918 (Czech, Slovak, Moravian, Bohemian, Rusyn, and German-Bohemian). Site in is English.
The SVU is a nonprofit, nonpolitical, cultural organization dedicated to the enhance and promote Czech and Slovak culture worldwide. Based in Washington, DC, it has branches throughout the US and across Europe. It hosts an annual World Congress. Site is in English.