A composite public cloud enables an automated marketplace system for, selling and trading of computational resources by aggregating available compute resources so that buyers are automatically matched with sellers. A listing of compute resources available on a prospective seller's system and bids by prospective buyers for resources offered is maintained. A seller uses a series of attributes to characterize an available resource for prospective buyers. Compute resources are presented in a form which can be easily quantified or compartmentalized. Prospective buyers search the marketplace system based on desired resource criteria. The marketplace continually evaluates the attributes of resources available for sale and the desired criteria of prospective buyers. The system attempts to match buyers and sellers, optimizing for the needs of both parties. If a desirable match is found, the marketplace system facilitates a transaction between both parties, making the purchased resource available to the buyer.