For sometime now I’ve gone back and forth on what is my personally preferred (LDAP) directory server; in particular between Sun Directory Server Enterprise Edition, OpenDS, and OpenLDAP. Each has advantages and trade-offs:

• DSEE: Not free, complex, but well trusted, exceptional scalability
• OpenDS: Free, super simple install and management GUI included, best starter directory for sure, but relatively new to the scene and thus needs to build more cred.
• OpenLDAP: Not the best scalability, not the best replication or feature list, but very extensible, extremely well known and supported, free. Advanced features much more straight forward than competitors due to flat config file (especially ACLs, TLS, etc)

So I put it to my loyal and educated readers… which is your directory of choice?