JOST is a audio host application for plugins that can be used as plugin itself, or be compiled as a cross bridge between multiple audio plugin technologies... It is the first open source multi-technology (internal, native vst, ladspa, dssi) host in linux. It will mainly host a chain of plugins per instance, publishing jack, alsa, and alsa_seq ports in order to be connected in your main stream flow. It is actually under heavy development, but it still has some very good features that make it a first class host.