Nuclear ForensX is a cross-platform project under construction, it is still in beta state.
It is planned to use for analyzing gamma spectroscopy data, to support professionals while drawing conclusions which nuclides are in the given probe data.
Supported files:
csv:
simple with two lines
first line: energy values
second line: intensity values
all values separated with comma

IEC:
supporting official *.iec files is highly experimental, please use with care