From the announcement:

> Announcing that the Apache Oltu committers have voted to retire the
> project due to inactivity. Oltu was an OAuth protocol implementation in
> Java. It also covers others "OAuth family" related implementations such
> as JWT, JWS and OpenID Connect.

See http://attic.apache.org/projects/oltu.html for details.

Replacing Oltu will also help us get rid of org.json...