The most significant advance in Windows capability since the introduction of Windows NT and 95 is the advent of 64-bit programming and the extension of Win32 to Win64. The combined API is generally referred to simply as the Windows API, and this has been the practice throughout the book. The Win64 API allows Windows to run the largest and most demanding enterprise and scientific applications. These 64-bit systems allow programs to use huge address spaces, larger than the 4GB limit imposed by 32-bit addresses.
This chapter describes Win64 status and benefits, the programming model, and portability and migration issues. These considerations apply regardless of the actual 64-bit processor or the specific Windows version supporting Win64. Program 16-1 shows the process of porting one of the previous examples.