Right click the background to bring up the context menu
Double click nodes to delete and modify them
Drag attribute nodes over text area nodes to combine them
Save & load projects using the toolbar in the upper-left
Press enter or space to select a node. You can then use the arrow keys to move the node around. You can then use the arrow keys to move the node around, press delete to remove it and press escape to cancel.
Press enter or space to select an edge. You can then press delete to remove it or press escape to cancel.