WBid is designed to run only on Windows. It can be run on a Macintosh but it requires some help.
Every program that runs on a computer is designed for a specific operating system (Windows, Mac, Linux, etc.). This means Windows programs only run on Windows and Macintosh programs only run on Mac's. Big software houses have versions for each (i.e. Microsoft Office) that are designed to look similar but under the hood they are very different applications. Occasionally you will even see distribution media (perhaps a CD or DVD) that says it works on both Windows and Mac; but when installed the media detects what platform it is running on and installs the appropriate, but different, application.
All is not lost. There are two ways to run WBid on your Mac.
1. If you have a dual-boot Macintosh you can boot to Windows and use WBid, or
2. You can use a class of programs called Windows Emulators (i.e. Virtual PC, VMWare, or Parallels) to run an "instance" of Windows on top of your Mac OS. Then, WBid can be installed and run from that instance of Windows.
If you do not want to use a Windows emulator program consider using one of the following bid sort programs designed to run on Macintosh: