Implementing support for other, open source operating systems inside the T2 SDE is not that hard at all. As many of the included packages are either plain ANSI C or C++ code that compile on any system anyway, or the platform dependant bits are already ported to the vast majority of systems adding a new OS kernel to T2 comes down to:
adding a suitable "kernel header" package
adding the matching C library)
adding the matching C compiler (if any other than GCC)
adding the kernel packages itself
adding some definitions such as registration of the kernel name to T2
adding other custom packages, e.g. for network and firewall utilities, graphic subsystem packages et al.