LDAP is a protocol for networked directories [L1 ].
There are four independent (?) implementations, ldapTcl, Matt Newman's LDAP extension [L2 ], Jochen Loewer's (see below), a derivative of the latter available in tcllib as of 2004, and Gareth Owen's tclLdap-pkg [L3 ] (but is this a derivative of an early tclLdap?). It would be particularly useful to compare the latter two.
I did a pure Tcl implementation of a ldap interface in June 99. See (Jochen Loewer). It is running since then very nicely to query a large enterprise wide people directory. Right now only the read/query parts of the protocol are implemented. However, the internal ASN layer is there, so it should be rather easy to extend it. Unfortunately I didn't release the code to the public yet. I thought about that several times. It would be ideal for tcllib or even standard tcl (like the http package). CL: ooooo. ASN.1 would be nice for tcllib.
ak: Tcllib head provides an (incomplete) asn package. Directly derived from the code in the ldap package.
Interesting LDAP-based applications include Owen's Ldapper [L4 ].
As of 2004, the major category of LDAP servers is instances of Microsoft's Active Directory.