This project is very much challenging and fascinating too. And Google Summer of Code is an incredible program for university students to get seriously involved in such projects and open source in general. Last year I worked on porting NetBSD userland to MINIX 3 as part of GSoC and believe me it was an invaluable experience for me which isn't even remotely possible without such program. This year I will work on porting GNU Compiler Collection to HelenOS ( http://blog.vivekp.me/2012/04/25/port-gcc-to-helenos-gsoc-pr... ) as part of GSoC and I am already very excited. I wish this guy good luck and thanks Google for running such amazing program successfully!
HelenOS looks very cool and a port of a compiler to it sounds like a great project!
But why GCC? GCC is the crufty old compiler of yesteryear. It's a solid workhorse but big and inflexible, and in my opinion its importance will be waning as LLVM/Clang matures. Had you considered porting LLVM/Clang instead?
HelenOS (http://www.helenos.org/) and Minix (http://www.minix3.org/) are fundamentally different. While Minix is POSIX compliant, HelenOS has been designed and developed from scratch, improving upon some of the broken legacy conventions in the way. It is not even POSIX compliant, though it has libposix library for now to ease the task of porting foreign sources!
HelenOS uses its own microkernel written from scratch and supports SMP, multitasking and multithreading on both 32-bit and 64-bit, little-endian and big-endian processor architectures, among which are AMD64/EM64T (x86-64), ARM, IA-32, IA-64 (Itanium), 32-bit MIPS, 32-bit PowerPC and SPARC V9.
HelenOS is infact one of the most portable microkernel operating system! Currently it's not as much developed as it's counterparts but it will become a complete and usable modern operating system very soon given the amount of activity going on in there.
