Oil leaking where head tube meets front fork - how to solve?

In looking at Mrs. NoWhammies bike after a ride this weekend, there seemed to be a lot of oil? Grease? Something else? At the junction between the head tube and the front fork.

Does this part of the bike need maintenance? If so, what maintenance exactly is required? And do I need any special tools such as torque wrench, etc.?

Thank you.