From Blood Wiki
INI-like text files aiming to store configuration in the form of group->key->value.
More than 1 value could be associated with a key (can store a tables).
Example of .NSX file:
[group1] key1=value1 # comment key2=value2 [group2]key=parm1&|parm2 key1=x|y key2=foo|bar
NSX files are part of NetherMenu framework