A command line utility to create and manage personal graphs, then write them to dot and make images with graphviz.
It manages a bunch of YAML files, one for each entity in the graph. Each file lists the incoming and outgoing links it has (could have listen only the outgoing, now that I'm tihnking about it).
Each run of the tool lets you select from existing nodes or add new ones to generate a single link type from one to one, one to many, many to one or many to many -- then updates the YAML files accordingly.
It also includes a command that generates graphs with graphviz, and it can accept a template file that lets you customize the dot that is generated and thus the graphviz graph.