I think joespeed has already provided a similar answer, but I’ll elaborate a little on the DDS and RTPS IP. (I work for RTI)
OMG has crisp IPR policies. All specifications and specification revisions fall under one the three IPR Modes: Non-Assert, RF-Limited, or RAND. (see http://www.omg.org/cgi-bin/doc?ipr/12-09-02.pdf).
Both DDS and RTPS are released under the “RF-Limited Terms,” the terms are copied below:
RF LIMITED TERMS
Each Obligated Party in an RF on Limited Terms IPR Mode Adoption or Revision Process covenants that it will grant to an unrestricted number of applicants a royalty and fee free, nonexclusive, worldwide, non-sublicensable, perpetual patent license to its Essential Claims on fair, reasonable, and non-discriminatory terms to make, have made, use, import, offer to sell, sell, and otherwise directly or indirectly distribute Covered Implementations of such OMG Formal Specification, provided that it may not impose any further conditions or restrictions beyond those specifically mentioned in Appendix B on the use of any technology or intellectual property rights or the behavior of the Licensee, but may include reasonable, customary terms relating to operation or maintenance of the license relationship, including choice of law and dispute resolution.
All the submitters to the DDS/RTPS specifications and their revisions, are “obligated parties” which means they agreed to grant licenses of any IPR that is essential to implement the specifications.