NOVELTY - In-vessel composting apparatus includes a shredder for shredding input materials, a horizontal drum (200), an insulated enclosure, an input hopper for passing the input materials through the shredder, a vent for permitting low pressure outgassing from the drum, temperature sensor (330), incremental drive rotation, exhaust fan, operator station and a controller.    USE - For processing food waste and biodegradable eating utensils and trays, yard waste, newspapers, and organic packaging materials, e.g. cardboard and paper container.    ADVANTAGE - The simple, reliable, efficient, in-vessel composting system produces a more consistent, higher quality, nutrient rich, end product.    DETAILED DESCRIPTION - In-vessel composting apparatus includes    (a) a shredder for shredding the input materials, configured and powered for rendering the input materials into particle size of not larger than 4 in3;    (b) a horizontal drum with an input end having an axial input port and a discharge end having a larger axial discharge port;    (c) an insulated enclosure within which the drum is contained;    (d) input hopper for passing the input materials through the shredder and into the first chamber;    (e) vent for permitting low pressure outgassing from the drum;    (f) incremental drum rotation for rotating drum in increments of less than one rotation about its axis, being initiated when the temperature in the second chamber is greater that 150degreesF;    (g) exhaust fan air changing system for exchanging air in the drum for outside air;    (h) an operator station and    (i) a controller communicating with the temperature sensor, incremental drum rotation, exhaust fan changing system and the operator station.    The drum is divided in length by interior partitions into first, second and third chambers. Each partition has an axial port by which adjacent chambers are connected. The axial ports are of sequentially larger diameter from input port to larger discharge port. The second chamber is longer than the first and third chambers. The diameter of the larger discharge port is less than one half of the diameter of the drum.    DESCRIPTION OF DRAWING(S) - The drawing shows a diagrammatic side elevation of the invented apparatus.    Base frame (10)    Adjustable legs (12)    Infeed section (100)    Horizontal drum (200)    Temperature sensor (330)    Coupling (410)