A system for additively manufacturing a composite part, the system comprising: a delivery guide, movable relative to a surface, wherein: the delivery guide is configured to deposit at least a segment of a continuous flexible line along a print path, wherein the continuous flexible line comprises a non-resin component and a thermosetting resin component, wherein the thermosetting resin component comprises a first part of a thermosetting resin and a second part of the thermosetting resin; the print path is stationary relative to the surface; the delivery guide comprises a first inlet, configured to receive the non-resin component, and a second inlet, configured to receive at least the first part of the thermosetting resin; and the delivery guide is further configured to apply the first part of the thermosetting resin and the second part of the thermosetting resin to the non-resin component within the delivery guide; and a feed mechanism, configured to push the continuous flexible line out of the delivery guide; wherein the delivery guide further comprises: a third inlet, configured to receive the second part of the thermosetting resin; and an internal mixing structure, configured to operatively combine the first part and the second part of the thermosetting resin within the delivery guide; wherein the delivery guide further comprises an outlet and a line passage which is concentric with a central longitudinal axis of the delivery guide and through which the non-resin component is pushed, the line passage extending from the first inlet to adjacent the outlet, the outlet being configured to provide an exit for the continuous flexible line from the delivery guide; and wherein the delivery guide further comprises a resin passage separate from the line passage and extending from the second inlet and the third inlet to adjacent the outlet, the internal mixing structure comprising one or more mixing guides positioned within the resin passage. a delivery guide, movable relative to a surface, wherein: the delivery guide is configured to deposit at least a segment of a continuous flexible line along a print path, wherein the continuous flexible line comprises a non-resin component and a thermosetting resin component, wherein the thermosetting resin component comprises a first part of a thermosetting resin and a second part of the thermosetting resin; the print path is stationary relative to the surface; the delivery guide comprises a first inlet, configured to receive the non-resin component, and a second inlet, configured to receive at least the first part of the thermosetting resin; and the delivery guide is further configured to apply the first part of the thermosetting resin and the second part of the thermosetting resin to the non-resin component within the delivery guide; and the delivery guide is configured to deposit at least a segment of a continuous flexible line along a print path, wherein the continuous flexible line comprises a non-resin component and a thermosetting resin component, wherein the thermosetting resin component comprises a first part of a thermosetting resin and a second part of the thermosetting resin; the print path is stationary relative to the surface; the delivery guide comprises a first inlet, configured to receive the non-resin component, and a second inlet, configured to receive at least the first part of the thermosetting resin; and the delivery guide is further configured to apply the first part of the thermosetting resin and the second part of the thermosetting resin to the non-resin component within the delivery guide; and a feed mechanism, configured to push the continuous flexible line out of the delivery guide; a third inlet, configured to receive the second part of the thermosetting resin; and an internal mixing structure, configured to operatively combine the first part and the second part of the thermosetting resin within the delivery guide; wherein the delivery guide further comprises an outlet and a line passage which is concentric with a central longitudinal axis of the delivery guide and through which the non-resin component is pushed, the line passage extending from the first inlet to adjacent the outlet, the outlet being configured to provide an exit for the continuous flexible line from the delivery guide; and wherein the delivery guide further comprises a resin passage separate from the line passage and extending from the second inlet and the third inlet to adjacent the outlet, the internal mixing structure comprising one or more mixing guides positioned within the resin passage.