metaobj – Meta­Post pack­age pro­vid­ing high-level ob­jects

METAOBJ is a large meta­post pack­age pro­vid­ing high-level ob­jects. It im­ple­ments many of PSTricks' fea­tures for node con­nec­tions, but also trees, ma­tri­ces, and many other things. It more or less con­tains boxes.mp and rboxes.mp. There is a large (al­beit not com­plete) doc­u­men­ta­tion dis­tributed with the pack­age. It is eas­ily ex­ten­si­ble with new ob­jects.