Annotation in Croquet

Hello everyone.

Julian Lombardi's Croquet Blog was an article talking about Annotation in
Croquet. there is also an screenshot of this in
www.opencroquet.org/index.php/Screenshots .
I would like to know if this is already available to use in croquet or do I
need to install something?

I doing a school work and this could be very useful even if it is in beta
stage.

Thanks in advance.