We released a

new version
of Zocalo in December. (There have already been about 50 downloads, even without an announcement.) It is available on SourceForge. It includes
some new configurable features for prediction market experiments: the
main one is that experiments can be run in which traders keep their
earnings across rounds within a session. (This allows experiments in
which there is progressive revelation of information over the session
about the underlying value.) In order to better support longer-lived
sessions, we fixed a bug that allowed data to overrun the right edge
of the trade history chart.

In parallel, we have started working on support for long-lived
markets. This is the main step needed to support internal markets
within a business or organization. In order to handle that, we’ll
need persistent data for trader’s accounts and book orders, as well as
an ability to display the price history to traders without requiring
that they be continuously connected to the market (this is currently
necessary for the experiments that Zocalo supports). I’m pleased to
say that I have integrated both
(open source Object-Relational Mapping software) and
JFreeChart (open source
Chart drawing) into Zocalo. Neither is called to the full extent
necessary for a usable long-term market, but both are being used
thoroughly enough to show us that the integration works and they are
being invoked appropriately. The next step is to ensure that all
aspects of users, accounts, and orders are persistent. I’m hopeful
that I’ll be able to demonstrate this functionality by the end of the
month. (This functionality is not yet in the released versions.
We’ll publish it as soon as its usable and stable.)