I saw this E-R diagram in an answer on Stack Overflow:
Does anyone know which software was used to create it?
I use LucidChart but that output is really nice!
Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. It only takes a minute to sign up.Sign up to join this community
Perhaps unsurprisingly, you're not the first person to be intrigued by the fancy, fancy pictures in that post. If you look at the comments section below, you can see user
nice diagram, what tool did you use?
...to which the poster
... I use Visio with custom smart shapes that I built to use the James Martin ERD visual convention and a custom line pattern that gives it a hand-drawn look.
You might try reaching out to Joel at his public contact info and asking if he's willing to share the extensions he used (although the original post is around ~6 years old at the time of this writing so don't be too disappointed if he's using something else by now).