transition from MS-DOS to Microsoft Windows. As a result, almost no new commercial applications were written in Clipper after 1995. By then, the "classically trained programmer" commonly used strong typing, in contrast to the original dBASE language. An evolution of Clipper, named VO, added strong typing but made it optional, in order to remain compatible with existing code. Four of the more important languages that took over from Clipper were Visual Basic, Microsoft Access, Delphi, and Powerbuilder. They all provided strong typing. Revival by third-parties The Clipper language is being actively implemented and extended by multiple organizations/vendors, like XBase++ from Alaska Software and FlagShip, as well as free (GPL-licensed) projects like Harbour and xHarbour. Many of the current implementations are portable (DOS, Windows, Linux (32- and 64-bit), Unix (32- and 64-bit), and macOS), supporting many language extensions, and have greatly extended runtime libraries, as well as various Replaceable Database Drivers (RDD) supporting many popular database formats, like DBF, DBTNTX, DBFCDX (FoxPro, Apollo, Comix, and Advantage Database Server), MachSix (SIx Driver and Apollo), SQL, and more. These newer implementations all strive for full compatibility with the standard dBase/xBase syntax, while also offering OOP approaches and target-based syntax such as SQLExecute(). Usenet The Clipper Usenet newsgroups are comp.lang.clipper and comp.lang.clipper.visual-objects. Programming in Clipper A simple hello world - application: ? "Hello World!" A simple data base input mask: USE Customer SHARED NEW clear @ 1, 0 SAY "CustNum" GET Customer->CustNum PICT "999999" VALID Customer->CustNum > 0 @ 3, 0 SAY "Contact" GET Customer->Contact VALID !empty(Customer->Contact) @ 4, 0 SAY "Address" GET Customer->Address READ Version history The various versions of Clipper were From Nantucket Corporation; the "seasonal versions", billed as "dBase compilers" Nantucket Clipper Winter'84 - released May 25, 1985 Nantucket Clipper Summer'85 - released 1985 Nantucket Clipper Winter'85 - released January 29, 1986 Nantucket Clipper Autumn'86 - released October 31, 1986 Nantucket Clipper Summer'87 - released December 21, 1987 From Nantucket Corporation; Clipper 5 Nantucket Clipper 5.00 - released 1990 Nantucket Clipper 5.01 - released April 15, 1991 Nantucket Clipper 5.01 Rev.129 - released March 31, 1992 and from Computer Associates; CA-Clipper 5 CA Clipper 5.01a - CA Clipper 5.20 - released February 15, 1993 CA-Clipper 5.2a - released March 15, 1993 CA Clipper 5.2b - released June 25, 1993 CA-Clipper 5.2c - released August 6, 1993 CA Clipper 5.2d - released March 25, 1994 CA-Clipper 5.2e - released February 7, 1995