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The Object Windows Library (OWL) is a Borland C++ object-oriented framework originally designed for Windows API. It was used in Turbo Pascal for Windows, Borland Pascal and their Borland C++ package. It was a competitor to the Microsoft Foundation Class Library (MFC). OWL had incomplete support by the Borland C++ IDE and wasn't always upwardly compatible from release to release. It was eventually deprecated in favor of the Visual Component Library (VCL), which is written in Object Pascal and included in Delphi and C++ Builder Studios. An open source internet community has released OWLNext,〔 a series of corrections and improvements to the original OWL, which also provide support for modern compilers. == History == In the early 1990s, Borland dominated the C++ market. In 1991 Borland introduced Borland C++ 3.0 with 'Application Frameworks' which included Turbo Vision for developing DOS applications and OWL for the Windows platform. C++ was just beginning to replace C for development of commercial software, especially with the rising of the Windows platform (and the complexity that it involves). This allowed OWL to gain some popularity. The first version implemented a proprietary extension called Dynamic Dispatch Virtual Tables (DDVT). This allowed objects to bind 'events' (windows messages) with 'methods' (functions). This mechanism avoided saturating the OO virtual function system with one function for each window message. In the next version of OWL, DDVT was replaced with a RESPONSE_TABLE, a macro-based mechanism, which is maintained today. A conversion tool (OWLCVT) was included to migrate code from OWL 1.0 to OWL 2.0. In 1992, Microsoft launched MFC. A DOS version of MFC was short lived. The Windows version was simply a wrapper around the Windows API and was criticized for not being truly object-oriented. In 1993, Borland launched Borland C++ 2.0 for OS/2 which included a version of OWL 2.0. OWL 2.0 used BIDS, the newer template library for 'container' or 'class library'. In April 1993, Borland and Novell settled an agreement to port OWL to Novell AppWare Foundation. AppWare Foundation was an API designed by Novell to be cross-platform, allowing to deploy applications on Mac, Windows and Unix clients and with several network services. The main tools for developing in AppWare were OWL and AppBuilder (a visual tool to link application loadable modules through an 'Application Bus').〔Morgan B. Adair (1994) "(The AppWare Foundation: An Overview )"〕 In January 1994, Borland launched Borland C++ 4.0 for Windows which also included OWL 2.0. It added Doc/View support, VBX controls, and OLE. Win16, Win32s and Win32 was supported (Windows 95, the Win32 successor of Windows 3.x appeared in August 1995). Late in 1994, Novell CEO Raymond Noorda resigned. Novell expansion plans were reconsidered, AppWare development was stopped and so was OWL for AppWare. In 1995 a group of original team members bought AppBuilder. In the same year, Software UNO (www.uno.com) offered a commercial port for OWL 2.0, to several platforms: AIX 3.2.5, DEC OSF/1 AXP, HP-UX 9.03, Linux 1.2, Solaris 2.x, Sun OS 4.1.x, and SVR4 fox x86. It was called WM_MOTIF. 〔Software UNO Ltd (1997) "(Software UNO Products and Services )"〕 Early in 1995, Borland C++ 4.5 with OWL 2.5 was launched. As it was launched before Windows 95, Borland promised a free upgrade for any incompatibility present in the final Windows 95 (when available). Versions 4.51 and 4.52 followed. OWL 2.5 also included the Object Component Framework (OCF) to ease OLE development. In August 1995, Microsoft released Windows 95 and Visual Studio 4.0. Contrary to popular belief, the inclusion of the MFC40.DLL with Windows 95 did not have a huge impact on the adoption of MFC. By 1995, Visual Studio 1.5 had already eclipsed Borland C++ in shipments, due partly to the volume and quality of documentation included with Visual Studio. The nearly seamless transition of MFC projects from Visual Studio 1.5 and Visual Studio 4.0 also contributed to its popularity. The instability of the original Borland C++ 4.5 and quirky treatment of OWL also persuaded many developers to drop Borland C++ and OWL in favor of Visual C++ and MFC. In 1996, Borland launched Borland C++ 5 for Windows, which included OWL 5, which was a major revamp of the library. In August 1997, Borland C++ 5.02 was introduced with slightly updated a version of OWL 5. A Japanese edition was also available. Additionally, the Borland C++ Builder has included OWL in the 'companion CD'. After that Borland concentrated development on the VCL framework which has been evolving alongside OWL since Delphi 1.0 launched two years before. VCL continues to be the main framework of Borland (now Codegear) for Windows and .NET platforms. Examples on how linkage OWL applications with VCL Forms (Dialogs) were included in the last version of Borland C++. Borland stopped selling Borland C++ 5.02 and OWL in late 1999. After Borland deprecated OWL, development was taken over by group and is called OWLNext which consists of patches to the original OWL source code.〔(OWLNext )〕 It was included in the partner discs of Borland C++ Builder 2007 and Borland C++ Builder XE.〔Embarcadero Technologies "(C++Builder XE Partner DVD )"〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Object Windows Library」の詳細全文を読む スポンサード リンク
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