A Compression Component by Catalyst Development Corp

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.

ActivePatch Advantages
Using ActivePatch has a number of important advantages over the common methods of software re-packaging or incremental updates:

Reduce the size of an update.
ActivePatch analyzes the original and updated file at the byte level, generating the smallest size patch file required to perform the update. This results in a significant reduction in the size of the patch, which translates into lower bandwidth usage, shorter download times and increased reliability.

Faster update creation and distribution.
Unlike re-packaging or creating incremental updates, generating a patch does not require the developer to create another program or modify an existing script (such as an InstallShield installation script) for each update that is released.

Improved technical support and customer satisfaction.
With the ability to easily generate patches for updated software, there is no reason to keep customers waiting for the next version. Your customers always have the latest version of your software, reducing the number of technical support issues for those defects which have already been corrected.

Lowered media and distribution costs.
The ability to distribute a small patch, rather than re-packaging the complete product, can significantly reduce the costs associated with creating and shipping media. In addition, the smaller size of the patch files means bandwidth savings when making the update available for download.

Complete integration with the application.
The ActivePatch SDK allows the developer to fully integrate the patching process within the application. This provides the flexibility to implement custom user interfaces, specialized processing on updated files or any other customization required during the patching process or after the patch has been applied.

Safety and security.
The patching process is designed to be completely safe, committing the update only if no problems are encountered during the process. The original and updated file version, checksum and digital signature (if any) are checked to ensure that the file was patched correctly. A patch may be encrypted so that a password is required before it can be applied. Because the patch consists only of the changes to a file, it requires that the user actually have the software installed on their system, and can help protect against illegal distributions of updates for your software.