What's the 'correct' way of registering/installing an Assembly to the GAC?

There seems to be lots of different ways to register assemblies with the GAC, as in, they 'work'. However, what's the "proper" way of doing it?

In response to Lou Franco (and gacutil):

I'm using Gacutil for development, but it seems to me to be not the proper way to install it, since gacutil isn't included in the basic .NET utilities past .NET 1.1 - it's only a developer tool.

Additional: Gacutil (as seen in responses below) is not redistributable, and therefore should not be used in any app that you intend to give to people who are not developers. AKA, customers. See This blog post (and comments) by Aaron Stebner.

In response to using WIX:

WIX might be great and all, but how does it work under the hood? What details makes the way WIX installs the assembly the right way to install it? How does it look it up? Is it a system/.NET call? Is there some call in a dll buried somewhere in System32 that needs to be made?

(Edit: it looks like WIX uses MSI under the hood. See my comments in the accepted answer.)

Final edit: It looks like the correct way to install an assembly to the GAC is using windows installer, and nothing else. I'm going to give Wix a try. Thanks all!

Solution 1:

With Wix I would do something like this:

<DirectoryRef Id="MyDirectory" >
    <Component Id="MyComponent" Guid="PUT-GUID-HERE" DiskId="1">
        <File Id="MyAssembly" Name="MyAssembly.dll" Assembly=".net" KeyPath="yes" Source="MyAssembly.dll" />
    </Component>
</DirectoryRef>

When you use the attribute Assembly=".net" for a file in WiX, it will create entries in the MsiAssembly and MsiAssemblyName table for this component and mark it as a GAC component.

Solution 2:

http://blogs.msdn.com/astebner/archive/2006/11/04/why-to-not-use-gacutil-exe-in-an-application-setup.aspx

It looks like the gacutil should be avoided; it's not a redistributable app. Instead, the 'proper' way of installing them seems to be using MSI, one way being WIX, as posted by CheGueVerra or another script.