I only found the oauth client library for nodejs. Does anybody know where I can find a server implementation?
I've just released OAuthorize, which is a suite of middleware for implementing an OAuth 1.0a server. It is highly modular, letting you tune it to meet your requirements. It integrates seamlessly with Passport for authentication, using passport-http-oauth to protect APIs using access tokens.
Update: OAuth2orize is now available. It follows similar patterns, but implements support for OAuth 2.0.