* XAD from PADL
In March 1998, Australian Luke Howard wrote Requests For Comments 2307 to the IETF (“An Approach for Using LDAP as a Network Information Service”). The following year, he founded PADL Software with the intent of implementing the RFC in products.
The resulting product, the NIS/LDAP Gateway (a.k.a. “ypldapd” which, to non-Unix geeks would imply a “yellow pages,” or Network Information Service), is a Network Information Service (NIS) server that uses LDAP as its information source. It permits existing NIS clients to transparently use LDAP to resolve user, group and host information. Organizations can take advantage of LDAP features, such as distribution and scalability, without upgrading their Unix clients. In reality, of course, Howard first created the product then wrote the RFC describing the implementation and then (when it was well received) went on to commercialize it.
But wait, there’s more.
PADL looked over the computing landscape and saw that offering a gateway service for Unix/Linux installations that used NIS could lead to a fairly limited niche. The company noticed that there were quite a few more Windows desktops than Unix and Linux desktops combined in the corporate world (or, for that matter, almost any “world” you could define). PADL had a very good LDAP implementation on Unix; it just needed to rope in the Windows identity services – Active Directory, to be precise. Thus was XAD born.
XAD, PADL’s most recent product, is a cross-platform enterprise identity management service that runs on Linux. It is based on open standards such as OpenLDAP and does not require a proprietary server infrastructure. The two key features of XAD are that it is a unified repository of identity information and it offers single sign-on and password management across all major operating systems, including Windows, Linux and Unix.
For Windows dominated networks, PADL supports cross-forest and domain trusts between Active Directory and XAD forests. However, replication is not supported between Active Directory and XAD domain controllers, and an XAD domain cannot be a member of an Active Directory forest. PADL has stated that it intends to address these limitations in an upcoming version of XAD. Interestingly, XAD can be hosted on Novell’s SuSE Enterprise Server. Whether you would prefer XAD or Novell’s own eDirectory could hinge on the exact makeup of your network. But if you do have Linux/Unix hosts as well as Windows desktops, then you should investigate XAD especially if you have a requirement (or a commitment) to use open source tools wherever possible.
