From Freelance Systems Development:
Barcoder128 is an ActiveX DLL component for use with all programming languages that support COM technology (Visual Basic, C++, and so on). Allowing Code 128 bar codes to be easily rendered on to any object which has a device context (screen, printers) with the minimum of code. Code 128 is an international bar coding algorithm that allows the coding of numeric, alphanumeric (upper and lowercase), and special characters. The algorithm has a built-in checksum operation for maximum scanner readability, resulting in excellent error correction. Code 128 can dynamically switch between three seperate encoding tables for alphaumeric variations and numeric characters. This switch can be done during the bar code, thus optimizing the bar code density. Pure numeric data is encoded at double the density of alphanumeric data, resulting in a very compact bar code.