The Object Management Group (OMG) Data Distribution Service (DDS) standard is what is called an "open standard." This means that the standard is publicly available and provides a normative reference to help guarantee consistency, portability and interoperability. An open standard is not the same thing as software that is "open source." Open source software is computer software made available with its source code. Open source software may be shared and modified and distributed, usually under an open source license. The DDS Standard is an open standard and has open source implementations available. For example, OpenDDS is an open source implementation of DDS managed by OCI (Object Computing Inc.). There are many commercial distributions that are available as well, the most popular being RTI's Connext® DDS.