I have been using FBB amateur radio software since early nineties. It was the time of DOS operating system, so most of us, system administrators (or, so called system operators - sysop's), used various packet radio software for DOS. Versions of FBB packet radio BBS software for DOS, today are known as DosFBB.
I still administer one DosFBB database in the SRV (Amateur Radio Union of Vojvodina, a part of SRJ). It is DosFBB v7.00g23 that runs on a 486DX computer with 16 MB of RAM and Hercules b/w graphics. Since last December, it runs without any re-boot (excepting some power failures). Before that, it was a bit tricky to set up all memory management properly, in order to avoid "frozen" system. Although this server runs under DOS, its "radio clients" don't depend on that. In fact, users of that DosFBB might run their client software under DOS, Windows, Linux or any other operating system that offer amateur packet radio abilities.
Two years ago, after I got my new box, Pentium 166 with 32 MB of RAM and VGA color graphics, I switched to a Windows version of FBB (so called WinFBB). Author of the software, an radio amateur from France, Jean-Paul F6FBB, has made many versions of WinFBB, including 16 bit variant for Windows 3.x and Windows 9x as well as 32 bit variant for Windows NT. I have run both variants until now (at the moment it is 16 bit WinFBB v7.00g25 that runs ok under Windows NT 4.0).
The main difference between DosFBB and WinFBB is that the second one offers you to do other jobs with your computer, while FBB is running as just any other application. Beside that, it is always nice to copy a text from another application (for example, from an Internet email) and to paste it into a packet radio message.
In the mean time, I upgraded my system to the Celeron 400 MHz with 96 MB of RAM and a big hard disk that has enough room to install Linux and try LinFBB ...