A method, comprising: performing, by one or more computing devices of a resource migration marketplace service: receiving, via one or more programmatic interfaces, a first request from a first client to enable access by one or more migration facilitators to a configuration record collection of the first client, wherein the configuration record collection comprises information associated with a plurality of computing environments of the first client; receiving, via the one or more programmatic interfaces, a particular migration candidate identification query from a particular migration facilitator of the one or more migration facilitators, wherein the particular migration candidate query indicates characteristics of candidate computing environments for migration to respective target environments and capabilities of the particular migration facilitator; generating a response to the particular migration candidate identification query wherein the response identifies a list of computing environments from the plurality of computing environments of said configuration record collection which match the characteristics of candidate computing environments and the capabilities of the particular migration facilitator; transmitting, via the one or more programmatic interfaces to the particular migration facilitator of the one or more migration facilitators, the response to the particular migration candidate identification query; receiving, from the particular migration facilitator via the one or more programmatic interfaces, a list of migration proposals comprising a first proposal associated with migrating at least a portion of a first computing environment of the plurality of computing environments to a second matching computing environment identified in the response; and providing, to the first client via the one or more programmatic interfaces, an indication of the first proposal associated with migrating, with the assistance of the particular migration facilitator, at least a portion of the first computing environment to the second computing environment. receiving, via one or more programmatic interfaces, a first request from a first client to enable access by one or more migration facilitators to a configuration record collection of the first client, wherein the configuration record collection comprises information associated with a plurality of computing environments of the first client; receiving, via the one or more programmatic interfaces, a particular migration candidate identification query from a particular migration facilitator of the one or more migration facilitators, wherein the particular migration candidate query indicates characteristics of candidate computing environments for migration to respective target environments and capabilities of the particular migration facilitator; generating a response to the particular migration candidate identification query wherein the response identifies a list of computing environments from the plurality of computing environments of said configuration record collection which match the characteristics of candidate computing environments and the capabilities of the particular migration facilitator; transmitting, via the one or more programmatic interfaces to the particular migration facilitator of the one or more migration facilitators, the response to the particular migration candidate identification query; receiving, from the particular migration facilitator via the one or more programmatic interfaces, a list of migration proposals comprising a first proposal associated with migrating at least a portion of a first computing environment of the plurality of computing environments to a second matching computing environment identified in the response; and providing, to the first client via the one or more programmatic interfaces, an indication of the first proposal associated with migrating, with the assistance of the particular migration facilitator, at least a portion of the first computing environment to the second computing environment.