The clang/LLVM based ELLCC project (http://ellcc.org), after having 
reached a huge milestone (http://ellcc.org/blog/?p=231) has now 
successfully compiled itself.

The steps were:
1. Use gcc to build the compiler with Linux standard libraries.
2. Use ecc to build itself with libc++, libc++ABI, libunwind, musl, and 
compiler-rt
3. Use the newly built compiler to build itself again.

One interesting side note: The compiler was 12MB smaller after it built 
itself.

ct-fw-88 ellcc 622 % size */Release+Asserts/bin/ecc

text    data     bss     dec     hex filename

52415858 2152024   84768 54652650        341eeea 
llvm-build/Release+Asserts/bin/ecc

40222706 2117136  135416 42475258        2881efa 
llvm-build-self/Release+Asserts/bin/ecc

Even more interesting, it was compiled statically. No dynamic libraries 
needed:

ct-fw-88 ellcc 623 % ldd */Release+Asserts/bin/ecc

llvm-build/Release+Asserts/bin/ecc:

linux-vdso.so.1 =>  (0x00007fff2ffff000)

libz.so.1 => /lib64/libz.so.1 (0x00007facd87e1000)

libpthread.so.0 => /lib64/libpthread.so.0 (0x00007facd85c4000)

libncurses.so.5 => /lib64/libncurses.so.5 (0x00007facd837c000)

librt.so.1 => /lib64/librt.so.1 (0x00007facd8173000)

libdl.so.2 => /lib64/libdl.so.2 (0x00007facd7f6f000)

libstdc++.so.6 => /home/de023789/gnulocal/lib64/libstdc++.so.6 
(0x00007facd7c6e000)

libm.so.6 => /lib64/libm.so.6 (0x00007facd7a18000)

libgcc_s.so.1 => /home/de023789/gnulocal/lib64/libgcc_s.so.1 
(0x00007facd7803000)

libc.so.6 => /lib64/libc.so.6 (0x00007facd74a5000)

/lib64/ld-linux-x86-64.so.2 (0x00007facd89f7000)

llvm-build-self/Release+Asserts/bin/ecc:

not a dynamic executable

ct-fw-88 ellcc 624 %

That is very cool.

-Rich