A timeline of steps. Every feature is a step in a list you can reorder, suppress, delete or roll back to, with a live editor for the selected step's values. Every edit is one Rhino undo step.
Parameters and configurations. Named values with expressions and units (thickness*2 + 1, 10 mm + 1 in), usable in any feature value. Steps and mates can be suppressed by a condition (holes == 0), and configurations switch whole sets of parameter values.
Sketches with constraints and dimensions. Profiles are defined by driving dimensions measured from the origin or the body's edges, on world XY, the top or bottom of a body, or any flat face. Drawn geometry takes constraints and dimensions, Fusion and Inventor style.
Holes and patterns. Simple, counterbore and countersink holes from a sketch's circles, through all or to a depth, and patterns of cuts and joins.
Edits that keep their references. Faces and edges are named by the step that made them, so a fillet's edges, a sketch's face and a mate's faces are found again after upstream changes.
Any Grasshopper component as a step. Run stock Grasshopper components (loft, sweep, revolve, chamfer and more) as timeline steps, bound to bodies, picked faces and edges, Rhino objects or parameters.
Multi-body parts and assemblies. Each body is its own object with a name, material and quantity. Place bodies as parts and mate their faces, cylinders or circular edges.
Fabrication and assembly sheets. Layouts with views and dimensions that update with the model, part drawings per body, and an assembly sheet with balloons and a parts list.