You can think of it as a precursor to LDAP.

It was a way to provide centralized access to User/Groups/Password and hostnames information over the network. YP was a staple of most UNIX deployments for some time, before being replaced by LDAP and DNS.

You'll find some historical context here [1].

[1] https://en.wikipedia.org/wiki/Network_Information_Service

Thanks!

Sibling comment links to the relevant Wikipedia page, but most people who've dealt with YP probably know it as NIS (turns out using a trademarked term wasn't ideal). https://lwn.net/Articles/874174/ is a discussion of the current state of the world - Fedora is considering removing support for it in a future release, but it's otherwise still hanging around in Linux distributions.

OK, suddenly I feel old. When I knew people using YP, we all knew that it was the rightful name, and NIS was the name slapped on it later due to trademark concerns...

If I'm not mistaken, Sun has made that mistake more than once. Bryan Cantrill has often pointed out that the original name of Solaris zones was Kevlar.

And don't forget Happy Meal Ethernet!

> https://lwn.net/Articles/874174/ is a discussion of the current state of the world - Fedora is considering removing support for it in a future release

Subscriber link: https://lwn.net/SubscriberLink/874174/693a5853d33f4b45/