Clear and Simple interface
Cross-Platform: YALA can be accessed from any platform using any modern browser
Theoretically works with any LDAP server, see README file for list of supported LDAP servers.
Reads the schema from the LDAP server and gets lots of useful information off there.
Entry Types recognition: You can configure YALA to recognize an entry of objectclasses X & Y, for example, as a user entry, have a special icon for it, and allow simple creation of new entries of this type (i.e. add a new user).
It's free (under the GPL)