RCDevs OpenID Provider is an OpenID 1.1 and 2.0 provider with simple registration and multiple OpenID URL formats. Compared to other OpenID provider implementations, RCDevs OpenID Provider is extremely easy to implement: provided that you have a working WebADM server, installation just consists of adding the OpenID WebApp in WebADM and adding a markup in the index page of your public Web site. The RCDevs OpenID Provider works with LDAP and OpenOTP authentication back-ends. With OpenOTP, your OpenID users can authenticate with any OpenOTP one-time password mechanism (Soft Tokens, SMSOTP, MailOTP, Yubikey, MobileOTP). RCDevs OpenID Provider supports both query-string-based OpenID URLs and hostname-based OpenID URLs. An example of the format using a query string is "http://rcdevs.com/?user=myuser&domain=mydomain" and an example of the format using a hostname is "http://myuser.mydomain.rcdevs.com/".