Since 12th. of December 2008 Switzerland is part of the Schengen agreement. For citizens of third countries (that is, countries that are not members of the EU/EFTA)  with a B or C residence permit, these means that they are not required to have a visa in order to be in the Schengen Area.In order to cross the border a valid passport and a valid residence permit is required.

Similarly non EU nationals living in an EU country and holding a valid resident permit in the EU country of residence, can travel to Switzerland without restriction.