US dollar is the standard integrated currency. You can add further currencies according to your desire and business pattern, this would require a bit of customization skill but one case still easily add a new currency through the Add New option.
Note: You can add as many currencies as you can but if you want to add new currency as base currency then you should have to edit base currency which is U.S.Dollar by default but value of base currency is 1 which is not changeable.