Can non-web applications use OpenID?

Question

How can I make my desktop application into an OpenID relying party?

Answer 1

Since OpenID has a specified protocol, it will either work all the time (assuming providers are conforming) or not at all. Additionally, since the OpenID protocol (at least the authentication bits, see the specification) consists of simple HTTP requests, you could implement the protocol in a desktop application assuming you know how to make such requests.

It is generally considered a bad idea though, since there are better technologies (OAuth) and it disrupts the user experience (being different from OpenID in a browser — see OpenID For Desktop Applications: How? When?).

Further reading: OpenID for Desktop Clients