Retractor systems and methods for retracting body tissue during surgery. The retractor system includes a rail having two opposed widened rail portions separated by a narrowed portion, each widened portion engageable by a separate clamp. The clamps are configured to support the rail to a fixed surface, or to support a surgical device. Each clamp may independently be positioned or slid along the rail to a desired location without interference with a clamp on an opposing widened rail portion. A device clamp is formed of spherical mating portions which enable alignment of a surgical device along six degrees of freedom, and tightenable by securing a single fastener. A retractor blade mount enables an angular and tilting disposition of a retractor blade, as well as remote manipulation of the retractor blade.