As T2 comes with a sophisticated build system with support for cross compiling including the bootstrap of a cross toolchain it is fairly easy to use T2 to build or port to new OS kernel.
In the beginning T2 was designed closely around Linus Torvald's Linux kernel. However as this support is fairly complete, now and also because other interesting kernel arrive at the horizon the T2 project took the next step forward to support multiple OS kernel.
Aside the sophisticated Linux support, Minix and OpenBSD support is being worked on.