diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..ef54053a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,66 @@
+/libretro-2048
+/libretro-3dengine
+/libretro-4do/
+/libretro-bluemsx/
+/libretro-bnes/
+/libretro-bsnes/
+/libretro-bsnes_cplusplus98/
+/libretro-bsnes_mercury/
+/libretro-catsfc/
+/libretro-config-user.sh
+/libretro-desmume/
+/libretro-dinothawr/
+/libretro-dosbox/
+/libretro-emux/
+/libretro-fb_alpha/
+/libretro-fceumm/
+/libretro-ffmpeg/
+/libretro-fmsx/
+/libretro-gambatte/
+/libretro-genesis_plus_gx/
+/libretro-gpsp/
+/libretro-handy/
+/libretro-hatari/
+/libretro-mame/
+/libretro-mame078/
+/libretro-mame139/
+/libretro-manifest/
+/libretro-mednafen_gba/
+/libretro-mednafen_lynx/
+/libretro-mednafen_ngp/
+/libretro-mednafen_pce_fast/
+/libretro-mednafen_pcfx/
+/libretro-mednafen_psx/
+/libretro-mednafen_snes/
+/libretro-mednafen_supergrafx/
+/libretro-mednafen_vb/
+/libretro-mednafen_wswan/
+/libretro-meteor/
+/libretro-mupen64plus/
+/libretro-nestopia/
+/libretro-nxengine/
+/libretro-o2em/
+/libretro-pcsx_rearmed/
+/libretro-picodrive/
+/libretro-ppsspp/
+/libretro-prboom/
+/libretro-prosystem/
+/libretro-quicknes/
+/libretro-remotejoy/
+/libretro-scummvm/
+/libretro-snes9x/
+/libretro-snes9x_next/
+/libretro-stella/
+/libretro-stonesoup/
+/libretro-tempgba/
+/libretro-tgbdual/
+/libretro-tyrquake/
+/libretro-uae/
+/libretro-vba_next/
+/libretro-vbam/
+/libretro-vecx/
+/libretro-virtualjaguar/
+/libretro-yabause/
+/libretrodb/
+/retroarch/
+/build-summary.log
diff --git a/libretro-config.sh b/libretro-config.sh
index 598d794d..c5baefe9 100755
--- a/libretro-config.sh
+++ b/libretro-config.sh
@@ -139,7 +139,37 @@ export RA_ANDROID_API=android-18
 # Retroarch minimum API level (defines low end android version compatability)
 export RA_ANDROID_MIN_API=android-9
 
-# Core build summary
+#OSX DEFINES
+#===========
+
+# Define this to skip the universal build
+# export NOUNIVERSAL=1
+
+# ARCHFLAGS is a very convenient way of doing this for simple/obvious cores
+# that don't need anything defined on the command line for 32 vs 64 bit
+# systems, however it won't work for anything that does.  For that, you need
+# to do two separate builds, one for each arch, and then do something like:
+#  lipo -create core_i386.dylib core_x86_64.dylib -output core_ub.dylib
+#
+# If building on 10.5/10.6, it's possible that you could actually build a UB
+# for Intel/PowerPC, but please don't. ;) Consider this a proof of concept
+# for now just to test a few cores.
+
+if [[ "${FORMAT_COMPILER_TARGET}" = "osx" && -z "${NOUNIVERSAL}" ]]; then
+   case "${ARCH}" in
+      i385|x86_64)
+         export ARCHFLAGS="-arch i386 -arch x86_64"
+         ;;
+      ppc|ppc64)
+         export ARCHFLAGS="-arch ppc -arch ppc64"
+         ;;
+      *)
+         echo "Universal build requested with unknown ARCH=\"${ARCH}\""
+   esac
+fi
+
+#CORE BUILD SUMMARY
+#==================
 
 # Set this to disable the core build summary
 # export NOBUILD_SUMMARY=1