These 2 files: - flamegraph.pl - stackcollapse-perf.pl are copied from: https://github.com/brendangregg/FlameGraph/blob/master/flamegraph.pl https://github.com/brendangregg/FlameGraph/blob/master/stackcollapse-perf.pl which are under license: https://github.com/brendangregg/FlameGraph/blob/master/docs/cddl1.txt