March 1995

LDAP standardized

RFC 1777 defined the Lightweight Directory Access Protocol in March 1995 — a TCPTransmission Control Protocol — a reliable, connection-oriented protocol used on the internet.-based standard for querying and updating directory services.

What it was for

Lightweight Directory Access ProtocolLDAP models organizations as a tree of entries (users, groups, printers) with attributes like `cn`, `mail`, and `memberOf`. It replaced heavier X.500 DAP for most deployments and became the backbone of Active Directory, OpenLDAP, and corporate SSO. Every 'sign in with your company account' flow still traces back to directory lookups LDAP made universal.

Companies

  • IETF

Why it's here

LDAP turned enterprise directories into a simple, interoperable network protocol.

Why it mattered

It became the standard way applications authenticate users and look up org structure at scale.

What it solved

Apps needed a lightweight way to read user and group data from centralized directories without proprietary APIs.

Media

  • Lightweight Directory Access Protocol
    ImageLightweight Directory Access Protocol

    Rferrero, CC BY-SA 4.0, via Wikimedia Commons

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