This invention relates generally to a novel method for joining at least one first self-supporting body to at least one second self-supporting body which is similar in composition to or different in composition from said at least one first self-supporting body and to novel products which result from such joining. In some of its more specific aspects, this invention relates to different techniques for joining ceramic matrix composite bodies to other ceramic matrix composite bodies of similar characteristics and for joining ceramic matrix composite bodies to bodies which have different characteristics (e.g., metals). The ceramic matrix composite bodies of this invention are produced by a reactive infiltration of a molten parent metal into a bed or mass containing at least one of a boron source material, a carbon source material, and a nitrogen source material and, optionally, one or more inert fillers.