ActivePatch is a software development kit that enables developers to create their own update in the form of a patch, and integrate the patch application process directly into their own software. Unlike other products, ActivePatch does not simply create incremental updates and re-package the files. It analyzes each file at the byte level and determines the best method for updating the target file on the user's system. It is designed to work on both text and binary files of any type including executables, libraries, data files and documents. ActivePatch can be used to create a patch of a single file or can be used to create an update for a complete product, modifying existing files, removing files that are no longer needed and creating the new files that have been added.

ActivePatch is available as a standard dynamic link library (DLL) and an ActiveX component, and can be used with virtually any Microsoft Windows development language or scripting tool. The ActivePatch API is designed to be simple enough to easily integrate into existing products, as well as offer a great degree of power and flexibility. ActivePatch comes with sample programs written in Visual Basic and C++, and includes utilities that simplify the creation and application of patches.