3+Share

3+Share was a pioneering file and print sharing product from 3Com. Introduced in the early 1980s, 3+Share was competitive with Novell's NetWare in the open systems network server business throughout the 1980s.

3+Share was a multitasking network server stack that ran on top of single-tasking MS-DOS. Internally, it had a network stack, file and print server modules, disk caching, user handling and more, all running simultaneously inside the DOS memory space. Because they were not limited by the PC memory map, 3+Share could support a megabyte or so of flat memory, breaking the PC's 640kb barrier. This was a large amount of RAM for the time.

3Com soon partnered 3+Share with dedicated server hardware called the 3Server, a combination which can be seen to be the first network-attached storage system. 3+Share included the EtherShare and EtherPrint protocols, which leveraged Xerox's XNS network protocol.

3Com and Microsoft jointly developed LAN Manager 2.0 as a successor to 3+Share, a product which was introduced in 1990. 3Com soon lost interest in the network software market, handing over its LAN Manager product (now called 3+Open) as well as its intellectual property to Microsoft in 1991. This work was absorbed into Microsoft and IBM's Server Message Block protocol, which is still used today.