Artisoft Inc, the Tuscon, Arizona network specialists, has developed a new version of its LANtastic local area network software for Windows NT. The company, which claims five million customers, says Windows NT, Windows 3.x, Windows 95, Dos and OS/2 systems can be combined in a single network. A public beta version of LANtastic for Windows NT is expected to be available for download next month at the firm’s web site: www.artisoft.com.