From the excellent overview website:
ProLine was the first communications product to truly link Apple II computers to the Internet (known as ARPANET back in the mid 1980s). Users connected via modem to exchange email and Usenet news. ProLine was essentially a version of Unix for the Apple II in less than 48K of memory. By the time I was 30, ProLine had consumed a third of my life.
The leading Apple II and Macintosh magazine, inCider/A+, awarded ProLine five full stars in the December 1992 issue, stating, "ProLine is as powerful as many UNIX minicomputer-based systems, yet amazingly, it runs on a standard Apple II. ProLine is top-notch. You can run ProLine as an independent on-line system, but it gains a new world of capabilities if you network it with other systems."
Hundreds of ProLine systems were scattered around the globe with sites running in every major country. This contribution to computer users of all denominations brought me more pleasure than notoriety or riches.
The highly-respected Boardwatch Magazine (June 1991) admitted, "ProLine is a network of Apple II systems that are not only tied to each other, but routinely carry Internet News Groups . . . something we just didn't expect. The speed and power of this BBS running on an Apple II were quite impressive."
ProLine shipped on two 3.5" 800K disks and originally sold for $259.95 -- a lot of money even today for an application. It consisted of scores of BASIC programs that presented a surprisingly accurate Unix-like environment, complete with a scriptable C-shell and online "man" pages. To produce a nice printed manual, I had to learn the PostScript language -- an investment that paid off again a dozen years later when it came time to make a PDF file out of the online manual.
My own ProLine system, named pro-sol, operated continuously for over 12 years. In the mid 90s, it interfaced via serial cable to a PC running FreeBSD Unix, connected to the Internet via ISDN. Through that box, you could actually telnet into ProLine. I took it down in 1996 when we moved to a new home and decided not to keep it going. Incredibly, some people are still running ProLine systems today, nearly 20 years after its inception.
Excerpt from the author's personal note on page 4:
"I started writing a BBS for my brand new Apple IIe, because there were no bulletin board systems that supported my modem back then ... ProLine introduced me to many friends and acquaintances, some long forgotten, but many who are good friends today. It allowed me to start my own software business, and helped me buy my first home. It was the reason that I met Dawn, sysop of pro-simasd. We married a couple of years later and have two wonderful kids!"
You've heard about people meeting on the Net and falling in love. I always thought they were kooky, until I realized that's exactly what happened to me, long before anyone had heard of web surfers and cyberspace. But, that's a story for another page.
My fondest memory of working on ProLine was in 1984 when Joe Holt, who wrote code for Beagle Bros, Adobe, and now Apple Computer, spent the summer at my house. He stayed up all night hacking away on ProLine, then would turn over his work and notes (in email) to me the next day to continue coding in between college classes. I'd pass the token to him that evening, and on it went for several weeks. (Trivia: Joe was best man at my wedding in 1990.)
ProLine inspired several other MDG products: ModemWorks, AmperWorks, OMM, and especially MD-BASIC. These started out as technologies used internally, only to be fashioned into commercial-grade, stand-alone products upon which ProLine depended.