If you are a developer who has done modifications to the source code of any WSO2 product, you can bundle your changes in a product patch and apply it to the system. You can apply various patches to the existing Carbon server to enhance the available features or to fix possible bugs. Therefore, applying patches is a convenient way of changing existing JAR files in Carbon applications. The Building from Source section in the documentation explains in detail how you can build Carbon products by modifying the source code.
See the following topics for details on how patches are created and applied: