../aolserver equates to /usr/local/src/aolserver/aolserver. This directory contains the following dirs.
nslog/ nsunix/ tcl8.3.2/
DISTRIBUTION.patch calls.imp nscgi/ nsodbc/ nsvhr/ tests/
DISTRIBUTION.txt doc/ nscp/ nspd/ scripts/ thread/
LICENSE.txt encoding-doc.html nsd/ nsperm/ tcl/ win32/
Makefile include/ nsext/ nssock/ tcl7.6/ windows-nsd.tcl
The actual nsd executable and source for it is in /usr/local/src/aolserver/aolserver/nsd/ dir.