Waterloo Expansion Pack

[BigDuke66]

While it looks similar to the HPS pack there are some PDT files of the JTS pack that are from 2013 instead 2012 and they also differ in size and comparing their content reveals that some things were fixed(like negative values removed in the weather data, AFAIK negatives values don't work at all) and adjusted(% modifier to terrain was lowered considerably).

Unlike with patches I think you can use the JTS pack on a HPS Installation as the different files only seem to be PDT files, that should still work no matter if HPS or JTS.