One of my big projects in the last week was setting up LDAP on my Linux server and configuring a Mac to use it for authentication. It took me a few days to get the server working, but once I understood the schema & naming conventions, I was able to figure it out easily.
I needed to test a piece of software which required administrative access but failed when using an Active Directory login. Since I don’t have an AD server, I was able to test it with LDAP by enabling it in Directory Access. I was able to log in with a userid defined on the server rather than locally and debug the software.