Kto (from Greek **: 'down', 'below', 'underneath') is an opinionated software-defined infrastructure (SDI) which governs diverse computing workloads and work-flows. Like in catabolism (from Greek ** kto, 'downward' and ** ballein, 'to throw'), the Kto system is the catalyst used to breakdown complex monolithic platforms into its fundamental microservices.
CoreOS is the foundation on which Kto is built. It provides the fundamental components used to assemble container-based distributed systems: etcd is used for consensus and discovery and rkt and docker are container engines.
All this CoreOS goodies are used to bootstrap a Mesos cluster. Mesos is a distributed systems kernel which abstracts compute resources away from machines. Accordingly, it provides schedulers (or frameworks in Mesos parlance) which can run on top in order to utilise the exposed compute resources.
Marathon is one of such frameworks. It is a cluster-wide init and control system for long-running applications. Other frameworks like Jenkins and Elasticsearch might coexist and share the same cluster resources.
REX-Ray delivers persistent storage access for container runtimes, such as Docker and Mesos, and provides an easy interface for enabling advanced storage functionality across common storage, virtualization and cloud platforms.