Chart::Gnuplot works with Gnuplot in Perl. Just setting the "terminal" option of the "chart" object (e.g. "x11" in Linux or "windows" in Windows) will pop up an interactive window with mouse hover feature, i.e.

my $chart = Chart::Gnuplot->new(
    terminal => "x11",
    ....
);
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Here has more examples about Chart::Gnuplot.