Abstract: Guide apparatus for guiding a tool such as a saw or router along a predetermined path relative to a workpiece has one or more track sections forming an elongate track parallel to the path to be followed by the tool. A tool-supporting carriage cooperates with the guide track so as to be guided by the track during movements of the tool. A stabilizer bar may be interlocked with the track in such manner as to prevent movement of the track laterally of the path along which the tool is to move.