Logic - Graph/Tree Editor!
- You link/unlink nodes (I called them entities! Xo) by right-click-dragging between them.
- You copy stuff by right-click-dragging to an empty space.
- You delete by grabbing something by left-click-holding and pressing the delete key.
- Oh, and nodes are completely tree structure expandable, just drag-drop attributes on nodes and nodes inside nodes.
(I know, not super intuitive; but very handy once you know about these.)
The editor uses lightweight rendering so you can have a ton of elements with good performance.