Sometimes I would like to include code in my project that is only available if certain libraries are loaded. Since I don't want to require these libraries as dependencies, but can't refer to their symbols either without them being loaded, things get a bit messy. This library attempts to provide a much more convenient way.
The project can be found on github including a fully documented symbol index and a getting started tutorial.
As of August 2014, Deferred is available on Quicklisp.
Deferred is licensed under the Artistic License 2.0.