public static List<IHtmlSchema> GetSchemas() { HtmlSchemaManager mng = new HtmlSchemaManager(); IHtmlSchema html = mng.GetSchema("http://schemas.microsoft.com/intellisense/html"); var schemas = mng.CustomAttributePrefixes.SelectMany(p => mng.GetSupplementalSchemas(p)).ToList(); schemas.Insert(0, html); return schemas; }