Chapter 2. Differences from upstream OpenJDK 11

OpenJDK in Red Hat Enterprise Linux contains a number of structural changes from the upstream distribution of OpenJDK. The Windows version of OpenJDK tries to follow Red Hat Enterprise Linux as closely as possible.

The most notable changes are the following:

  • On Red Hat Enterprise Linux, we dynamically link against native libraries such as zlib for archive format support and libjpeg-turbo, libpng, and giflib for image support. Likewise, we dynamically link against Harfzbuzz and Freetype for font rendering and management.

    On Microsoft Windows, these libraries are built from the sources of the corresponding Red Hat Enterprise Linux RPMs and packaged as dynamic-link libraries (DLLs).

  • On Red Hat Enterprise Linux, system-wide timezone data files are used as a source for timezone information.

    On Microsoft Windows, the latest available timezone data from Red Hat Enterprise Linux is included.

  • On Red Hat Enterprise Linux, system-wide CA certificates are used.

    On Microsoft Windows, the latest available CA certificate from Red Hat Enterprise Linux is used.

  • The src.zip file includes the source for all of the JAR libraries shipped with OpenJDK.