Per Wikipedia…

TRON does not specify the source code for the kernel, but instead is a “set of interfaces and design guidelines” for creating the kernel. This allows different companies to create their own versions of TRON, based on the specifications, which can be suited for different microprocessors.

It’s not even a software project as we know it. It’s a specification like POSIX, and presumably, anything implementing the spec can be certified if it passes a test suite, like UNIX.