Methods, apparatuses, systems and software for ion beam milling or machining are disclosed. The apparatus includes a specimen holder, a table, one or more ion sources, rotatable ion optics, and an imaging device. The specimen holder is configured to hold a specimen in a stationary position during milling or machining. The table is configured to change the stationary position of the specimen holder in any of three orthogonal linear directions and an angular direction. The rotatable ion optics are configured to emit an ion beam towards a predetermined location on the specimen from any of the one or more ion sources at any angle around an axis that is orthogonal to a horizontal surface of the table when the angular direction of the table is 0°. The imaging device is configured to generate an image of the specimen including the predetermined location, thereby enabling real-time monitoring of the milling or machining process.