NewLisp 8.4.3 for Slackware 10.1 was accepted by linuxpackages.net with an acceptance grade of 3 ("excellent").
Direct link:
http://www.linuxpackages.net/pkg_details.php?id=5848
The 8.4.0 package was created for Slackware 10.0 and is still hosted by linuxpackages.net:
http://www.linuxpackages.net/pkg_details.php?id=5451
Peter