Can a Linux LDAP server support Linux, Solaris, and Windows clients?

[LoveLinux2009]

My current environment consists of Linux servers, Solaris servers, and Windows servers and clients. We have no AD (Active Directory) in our Windows environment. I have the following two questions please:

1- If I make a couple of Linux boxes to be my LDAP servers (master & slave), can they support Solaris & Windows servers/clients as their clients w/o AD?

2- Can LDAP replace internal DNS? If so, is Internal DNS it's primary role or it is best used for SSO (Single Sign On)?

Obviously this is more of a architectural type question and as such I would greatly appreciate a guru's point of view.

Many thanks in advance, and have a terrific day.

[Irithori]

is Internal DNS it's primary role or it is best used for SSO

Well.. first of all:
A ldap server is a hierarchical database.
And a empty one at the beginning.
Similar to -for example- a MySQL DB, it can be used for all kinds of datastoring.

It *can* be a basis for authentication, *nix OSes might be easier here than windows, as one just ( ) has to configure pam, etc.
Windows authentication.. I am not up to speed in terms of samba/kerberos/ldap.
But last time I checked it was still a pita to setup and maintain.

Ldap can be a backend db of a dns server, but ldap itself is not a dns server.