Additional metalanguages are defined in other UDI Specifications:
The following UDI metalanguages have been defined by other organizations:
There are a number of additional metalanguages on the Project UDI "wish list". Of these, the following are currently being actively worked on:
We're looking for volunteers to help with the following that are high on the wish list:
Other specifications being developed outside of Project UDI are also defining additional UDI metalanguages. (See Related Specifications.)