The Free On-line Dictionary of Computing (18 March 2015):
Tymshare's operating system which ran
for many years on Tymshare's PDP-10s. It was a descendent
of TOPS-10 but had many of the important features of
TOPS-20 such as real paging and controllable/spawnable
processes. TYMCOM-X, one of the best kept secrets in the
PDP-10 folklore, was written by Bill Weiher, Vance Socci
, Allen Ginzburg, Karen Kolling, Art
Atkinson, Gary Morgenthaler (founder of the company that
produced IDRIS), Todd Corenson and Murray Bowles. Some
copies still run today. Most TYMNET development was done
under TYMCOM-X and Tymshare sold a TYMCOM-X system to TRW to
use in their credit reporting network, which was based on a
purchased copy of TYMNET circa 1979.
[E-mail from Vance Socci 1994-05-20].