The term Listserv (written by the registered trademark licensee, L-Soft International, Inc., as LISTSERV) has been used to refer to electronic mailing list software applications in general, but is more properly applied to a few early instances of such software, which allows a sender to send one email to the list, and then transparently sends it on to the addresses of the subscribers to the list.
The original Listserv software, the Bitnic Listserv (also known as BITNIC LISTSERV) (1984–1986), allowed mailing lists to be implemented on IBM VM mainframes and was developed by Ira Fuchs, Daniel Oberst, and Ricky Hernandez in 1984. This mailing list service was known as [email protected] (also known as [email protected]) and quickly became a key service on the BITNET network. It provided functionality similar to a UNIX Sendmail alias and, as with Sendmail, subscriptions were managed manually.
In 1986, Éric Thomas developed an independent application, originally named "Revised Listserv" (also known as "Revised LISTSERV"), which was the first automated mailing list management application. Prior to Revised Listserv, email lists were managed manually. To join or leave a list, people would write to the human list administrator and ask to be added or removed, a process that only got more time-consuming as discussion lists grew in popularity.
By 1987, the users of the Bitnic Listserv had migrated to Thomas' version.
Listserv was freeware from 1986 through 1993 and is now a commercial product developed by L-Soft, a company founded by Listserv author Éric Thomas in 1994. A free version limited to ten lists of up to 500 subscribers each can be downloaded from the company's web site.
Several other list management tools were subsequently developed, such as Lyris ListManager in 1997, Sympa in 1997, GNU Mailman in 1998.
In 1986, Éric Thomas developed the concept of an automated mailing list manager. Whilst a student at Ecole Centrale Paris, he developed the software now known as LISTSERV. Some of the early software features allowed joining or leaving a list without the need for human administration. Also, the list owner could add or remove subscribers, and edit templates for both welcome and system messages. Amongst other innovations LISTSERV introduced double opt-in in 1993 and the first spam filter in 1995.
After the release of Thomas' LISTSERV in 1986, [email protected] was enhanced to provide automatic list management, but was abandoned a few months later when Bitnic installed Thomas' LISTSERV.
Other than their name, Bitnic's and Thomas' products are unrelated and neither product is based on the other product's code.
Though electronic mailing lists (also known as "email lists") are not as popular as they once were, they continue to be used today due to their ease of use.
LISTSERV was registered as a trademark with the U.S. Patent and Trademark Office in 1995, based on its use since 1986. It was registered with the Swedish Patent and Registration Office, PRV, in 2001. As such, in those jurisdictions, using the word "listserv" to describe a different product or as a generic term for any email-based mailing list of that kind is a trademark misuse. The standard generic terms are electronic mailing list, elist, or email list for the list itself, and email list manager or email list software for the software product that manages the list. Nevertheless, the generic use of the term has been common at times.
Through version 15.0, individual user passwords were stored in the clear, and available to users who are listed as Site Managers or "Postmasters" in the application configuration, thus allowing unethical managers, or attackers who compromise the site, to easily try to reuse the username and password on other sites. Passwords are hashed to protect against this since version 15.5, which was released in 2007.
LISTSERV is available in several licensing options: LISTSERV Lite Free Edition for non-commercial hobby use; LISTSERV Lite for smaller workloads; LISTSERV, the standard, full-featured version; LISTSERV HPO (High Performance Option); and LISTSERV Maestro (for customized and targeted email publishing and reporting).
A list of currently-supported operating systems can be found at http://lsoft.com/products/listserv_os.asp