If you mean "largest monolithic piece of code" then yes
Posted Sep 4, 2008 23:23 UTC (Thu) by nix (subscriber, #2304)
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I've looked at glibc nscd. Neat, fast, efficient, config file format and
means of operation entirely undocumented (who needs network serialization
when you can just shared-mmap() sparse files and read directly from the
deserialized representation of the service files).
It's enormously more efficient than the Solaris ncsd used to be back in
the day, which I can remember constantly chewing up *40%* of CPU time on
an early UltraSPARC back in the late 90s. (Of course, that was a slower
CPU, but still.)