OpenJDK is an open-source implementation of the Java Platform, Standard Edition (Java SE). It provides developers with the tools and libraries needed to create Java applications. Being open-source means that anyone can use, modify, and distribute it freely, fostering collaboration and innovation within the programming community. OpenJDK is maintained by the OpenJDK Community, which includes contributors from various organizations and individuals. It serves as the reference implementation for Java SE, ensuring that it adheres to the specifications set by Oracle, the original creator of Java. This makes OpenJDK a reliable choice for developers looking to build cross-platform applications.