Enabled by the publication of unit output in real time (one of the rule changes) version 4 was first released in late 2010 with an early iteration through the popular ‘Schematic’ style representation of unit output in a particular region, also incorporating the live view of intra-regional transmission flows that was available as an optional extra in the TNSP data sets.
This was version 4.0.4 on 1st November 2010:
The specifics of the ‘Schematic’ widget have advanced considerably since that time, but the general approach remains (more than 10 years later) as something highly valued by clients for the clarity provided in delivering insights across a large and dynamic data set.