Online
ezmlm, a qmail-based MLM
cr.yp.to/ezmlm.html
Majordomo, a popular MLM used with sendmail
www.greatcircle.com/majordomo
Lyris, an MLM for Windows NT
www.lyris.com
Listar, an Open Source modular MLM for Linux
www.listar.org
L-Soft's Listserv MLM for Linux or Windows NT
www.listserv.net
CREN ListProc, a UNIX MLM
www.listproc.net