This very simple application is meant to be the handler on a domain that handles Cool Uri's (http://www.w3.org/TR/cooluris/) with 303 redirects.
All it does is map Uri's to other uri's and redirect them. To make thing easy you can either redirect by hitting the full URI (eg. [http://id.example.com/foo/15]{.title-ref}) or by querying a handle service (eg. [http://id.example.com/handle?uri=http://id.example.com/foo/15]{.title-ref}). Both of these will redirect you. The handle service also works for non-http URI's. Finally, there's a service that just returns information without performing a redirect, eg. [http://id.example.com/uris?uri=http://id.example.com/foo/15]{.title-ref}. This can be handy to bypass some of the strangeness that happens when you combine Cool uri's with CORS and custom HTTP headers.
Configuration is done by editing a YAML file. For each URI you need to register a regex and a redirect template. The regex should use named placeholders, as well as the redirect string. An optional argument [mount]{.title-ref} determines if your [match]{.title-ref} is living at the server root or is absolute (eg. because it's a URN). Not setting [mount]{.title-ref} sets it to [True]{.title-ref}.