I\'m working on a web service which requires a new GUID()
passed as a reference to a method within the service.
I am not familiar with C#
According to Is there any difference between a GUID and a UUID?
GUID is Microsoft's implementation of the UUID standard.
So, here's a link to libraries, that let's you create UUIDs of the following types:
https://github.com/search?p=1&q=uuid+php&ref=cmdform&type=Repositories
I don't know exactly, which one C# is using, but that's at least something you can use if you're writing some piece of software and want to have universal unique identifiers.
My perfered choice was https://github.com/fredriklindberg/class.uuid.php because it is just a simple PHP file and the most rated one (https://github.com/ramsey/uuid) had to much dependencies on other libraries, but his may change soon (see https://github.com/ramsey/uuid/issues/20).
But if you really need a GUID (according to the Microsoft standard), they have a different generation process than these 4122. Wikipedia claims that
GUIDs and RFC 4122 UUIDs should be identical when displayed textually
http://en.wikipedia.org/wiki/Globally_Unique_Identifier#Binary_encoding
In most cases, you should be fine by going for one of the PHP libs for UUIDs. I don't think you're meddling with Microsoft Component Object Model (COM), don't you?