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[[!meta title="What Is the GNU Hurd?"]]

The Hurd is the GNU project's replacement for the [[Unix]] kernel.

The Hurd is firstly a collection of protocols formalizing how different
components may interact.  The protocols are designed to reduce the mutual
[[trust]] requirements of the actors thereby permitting a more
[[extensible|extensibility]] system.  These include interface definitions to
manipulate files and directories and to resolve path names.  This allows any
process to implement a file system.  The only requirement is that it have
access to its backing store and that the [[principal]] that started it own the
file system node to which it connects.

The Hurd is also a set of servers that implement these protocols.
They include file systems, network protocols and authentication.
The servers run on top of the [[microkernel/Mach]] [[microkernel]] and use
Mach's [[microkernel/mach/IPC]] mechanism to transfer information.

The Hurd supplies the last major software component needed for a complete
[[GNU_operating_system|running/gnu]] as originally conceived by Richard
M. Stallman (RMS) in 1983.  The GNU vision directly drove the creation and has
guided the evolution of the [Free Software Foundation](http://fsf.org/), the
organization that is the home of the [GNU project](http://gnu.org/gnu/).

The Hurd development effort is a somewhat separate project from the
[[Debian_GNU/Hurd|hurd/running/debian]] port.


Read about what the GNU Hurd is [[gramatically_speaking]].

Read about the [[origin_of_the_name]].