Single-User, runs on one computer:

Big Business 5.0.3 for Windows [21MB]
Big Business 5.0.3 for Mac OS X [20MB]
Big Business 5.0.3 for Mac OS 9.2 [28MB]

Server, runs on a server computer:

Big Business 5.0.3 Server for Windows [28MB]
Big Business 5.0.3 Server for Mac OS X [25MB]

Client, runs on a client computer:

Big Business 5.0.3 Client for Windows [10MB]
Big Business 5.0.3 Client for Mac OS X [11MB]
Big Business 5.0.3 Client for Mac OS 9.2.2 [14MB]