After working with linux for years in small networks, I've started in a company that maintains large windows networks. I know you can cobble a linux host onto an Active Directory network but is there a tidy linux-y way of handling it if you didn't have to deal with Windows hosts. Purely hypothetical.
The closest equivalent to Active Directory for Linux is FreeIPA. FreeIPA is made by Redhat, and provides both LDAP and Kerberos based authentication to a Linux network...
FreeIPA is an integrated security information management solution combining Linux (Fedora), 389 Directory Server, MIT Kerberos, NTP, DNS, Dogtag (Certificate System). It consists of a web interface and command-line administration tools.
Bear in mind, FreeIPA is largely Redhat only, and would take a good bit of work to get up-and-running on Debian/Ubuntu/whatever...
LDAP is an application protocol for accessing and maintaining distributed directory information services over an Internet Protocol (IP) network.
Directory services may provide any organized set of records, often with a hierarchical structure, such as a corporate email directory. Similarly, a telephone directory is a list of subscribers with an address and a phone number.
I have seen large networks of over a thousand Linux servers with no centralized user authentication or management. Every single server had only local accounts that all had to be maintained individually.
That makes me cringe. Something like Puppet can probably help in that department of synchronizing accounts across systems, but it won't help you join the hosts to an AD domain.
I don't believe your question is about an Active Directory equivalent for Linux, such as FreeIPA. I think your question is about integrating Linux hosts into an existing Microsoft Active Directory such that your Windows machines and Linux machines are all commingled in there in the same directory.
You already know, as you said, that the Linux hosts can be "cobbled in there." I agree with that metaphor, as it's a messy process in my opinion.
Then, there also exist professional solutions such as PowerBroker (formerly Likewise) that is install-able on your Linux hosts and makes joining them to an AD domain much more reliable. It even incorporates some group policy capabilities.
I think you're likely to see something like that in a large enterprise that wants to join its Linux machines to a Windows domain.
This link is really old, but it highlights some of the performance differences between OpenLDAP and 389 Directory server (included in FreeIPA):
Of course, I'm sure both products have improved since then. I know OpenLDAP's numbers are a lot better, especially with the new mdb memory-mapped backend.
If I wasn't in a particularly security-conscious environment, I'd use NIS. It's lightweight, works on many Unices, deals well with server failure (ie, provided each client is either configured to use multiple NIS servers, or can find multiple servers by broadcast, it's robust against the failure of the currently-bound server), and has been used for years (as in, I remember configuring NIS servers in 1991) so its idiosyncrasies are pretty well understood.