There was a 4os2 netlabs project since a long time. There are 4.xx versions floating around on various places in the net. But the 4.xx branch was dropped in favour of the 'more' offical 3.xx branch which is in the repository at - http://perforce.openwatcom.org:4000/@md=d&cd=//depot/public/&c=TNZ@//depot/public/4os2/?ac=83 

Most probably there was no work on the 4.xx branch since years, while there was continuous development on the 3.xx branch by Michal Necasek and Steven Levine.

Starting with version 3.05x Andreas Buchinger made a few changes to the 4os2 sources. Andreas goal was to replace the cmdshl from the mlrxshl package which he used for many years. As probably every potential contributor will have the same questions Andreas had, we thought it would be a good idea to refresh the 4os2 pages here and make a netlabs project out of the perforce 3.xx branch.