diff --git a/build_loose.sh b/build_loose.sh
index 4a5b07a..a1971c4 100755
--- a/build_loose.sh
+++ b/build_loose.sh
@@ -26,8 +26,17 @@ find_file ()
 
 	find "./_tmp" -type f -name "${SEARCHNAME}" | while read FOUND
 	do
-		CHECK=$(sha256sum "${FOUND}" | cut -d ' ' -f 1)
-		#echo "$CHECK == $2"
+		# GNU vs non GNU
+		if [ -x "$(command -v sha512sum)" ]
+		then
+			CHECK=$(sha256sum "$FOUND" | awk '{ print $1 }')
+		elif [ -x "$(command -v sha512)" ]
+		then
+			CHECK=$(sha256 -q "$FOUND")
+		else
+			echo "No tool to validate sha256 sums with!"
+			exit 2
+		fi
 		
 		if [ "${CHECK}" = "$2" ]
 		then
diff --git a/build_pak0.sh b/build_pak0.sh
index d40d91b..b82795d 100755
--- a/build_pak0.sh
+++ b/build_pak0.sh
@@ -18,21 +18,28 @@ then
 fi
 
 PAK0_OUTDIR="$(pwd)/_build/halflife/$1-pak0"
-FINAL_TEST=$(cat "sums/$1_pak0.sha512" | cut -d ' ' -f 1)
+FINAL_TEST=$(cat "sums/$1_pak0.sha512" | awk '{ print $1 }')
 
 find_file ()
 {
 	SEARCHNAME=$(basename "${1}")
 
-	#echo "Looking for $SEARCHNAME"
-
 	if [ ! -z "$HL_STEAM_INSTALL" ]
 	then
 		find "$HL_STEAM_INSTALL" -type f -name "${SEARCHNAME}" | while read FOUND
 		do
-			CHECK=$(sha256sum "${FOUND}" | cut -d ' ' -f 1)
-			#echo "$CHECK == $2"
-		
+			# GNU vs non GNU
+			if [ -x "$(command -v sha512sum)" ]
+			then
+				CHECK=$(sha256sum "$FOUND" | awk '{ print $1 }')
+			elif [ -x "$(command -v sha512)" ]
+			then
+				CHECK=$(sha256 -q "$FOUND")
+			else
+				echo "No tool to validate sha256 sums with!"
+				exit 2
+			fi
+
 			if [ "${CHECK}" = "$2" ]
 			then
 				mkdir -p "${PAK0_OUTDIR}/$(dirname $1)"
@@ -49,8 +56,17 @@ find_file ()
 
 	find "./_tmp" -type f -name "${SEARCHNAME}" | while read FOUND
 	do
-		CHECK=$(sha256sum "${FOUND}" | cut -d ' ' -f 1)
-		#echo "$CHECK == $2"
+		# GNU vs non GNU
+		if [ -x "$(command -v sha512sum)" ]
+		then
+			CHECK=$(sha256sum "$FOUND" | awk '{ print $1 }')
+		elif [ -x "$(command -v sha512)" ]
+		then
+			CHECK=$(sha256 -q "$FOUND")
+		else
+			echo "No tool to validate sha256 sums with!"
+			exit 2
+		fi
 		
 		if [ "${CHECK}" = "$2" ]
 		then
@@ -92,7 +108,17 @@ cp -v "games/$1.dat" "$PAK0_OUTDIR/src/files.dat"
 cd "$PAK0_OUTDIR/src/"
 qfiles -pak 0
 
-FINAL_CHECK=$(sha512sum "$PAK0_OUTDIR/pak0.pak" | cut -d ' ' -f 1)
+# GNU vs non GNU
+if [ -x "$(command -v sha512sum)" ]
+then
+	FINAL_CHECK=$(sha512sum "$PAK0_OUTDIR/pak0.pak" | awk '{ print $1 }')
+elif [ -x "$(command -v sha512)" ]
+then
+	FINAL_CHECK=$(sha512 -q "$PAK0_OUTDIR/pak0.pak")
+else
+	echo "No tool to validate sha512 sums with!"
+	exit 2
+fi
 
 echo "Desired SHA512:   ${FINAL_TEST}"
 echo "Generated SHA512: ${FINAL_CHECK}"
diff --git a/build_tools.sh b/build_tools.sh
index 9b64701..48e9643 100755
--- a/build_tools.sh
+++ b/build_tools.sh
@@ -2,6 +2,27 @@
 
 set -e
 
+MAKEVER=$(make --version | awk '{ print $1 }' | head -n 1)
+
+# is this GNU?
+if [ "$MAKEVER" = "GNU" ]
+then
+	MAKETOOL="make"
+else
+	# guess not, do we have gmake?
+	if [ -x "$(command -v gmake)" ]
+	then
+		MAKEVER=$(gmake --version | awk '{ print $1 }' | head -n 1)
+		if [ "$MAKEVER" = "GNU" ]
+		then
+			MAKETOOL="gmake"
+		else
+			echo "Please install GNU Make."
+			exit 2
+		fi
+	fi
+fi
+
 DEPSDIR="$(pwd)/_deps"
 BINDIR="$(pwd)/_bin"
 INCTOOLDIR="$(pwd)/tools"
@@ -20,23 +41,23 @@ mkdir "$DEPSDIR"
 mkdir "$BINDIR"
 cd "$DEPSDIR"
 
-git clone https://notabug.org/CYBERDEViL/REWise
+git clone https://vcs.vera-visions.com/eukara/REWise
 cd REWise
-make
+$MAKETOOL CC=cc
 mv -v rewise "$BINDIR/rewise"
 
 cd "$DEPSDIR"
-git clone https://github.com/RavuAlHemio/hllib
-cd hllib/HLLib
-make
+git clone https://vcs.vera-visions.com/eukara/HLLib
+cd HLLib/HLLib
+$MAKETOOL CC=cc CXX=c++
 cd ../HLExtract
-make
+$MAKETOOL CC=cc CXX=c++
 mv -v hlextract "$BINDIR/hlextract"
 
 cd "$DEPSDIR"
 git clone https://github.com/yquake2/pakextract
 cd pakextract
-make CC=cc
+$MAKETOOL CC=cc
 mv -v pakextract "$BINDIR/pakextract"
 
 cd "$INCTOOLDIR/bmpfix"
diff --git a/dl_sources.sh b/dl_sources.sh
index fcf1565..ba11d44 100755
--- a/dl_sources.sh
+++ b/dl_sources.sh
@@ -6,7 +6,7 @@ set -e
 fetch_resource()
 {
 	BASENAME=$(basename "$1")
-	SHA512FILE=$(cat "./sums/$BASENAME.sha512")
+	SHA512FILE=$(cat "./sums/$BASENAME.sha512" | awk '{ print $1 }')
 
 	if [ ! -f "$BASENAME" ]
 	then
@@ -15,7 +15,17 @@ fetch_resource()
 		printf "\n"
 	fi
 
-	SHA512SUM=$(sha512sum "$BASENAME")
+	# GNU vs non GNU
+	if [ -x "$(command -v sha512sum)" ]
+	then
+		SHA512SUM=$(sha512sum "$BASENAME" | awk '{ print $1 }')
+	elif [ -x "$(command -v sha512)" ]
+	then
+		SHA512SUM=$(sha512 -q "$BASENAME")
+	else
+		echo "No tool to validate sha512 sums with!"
+		exit 2
+	fi
 
 	if [ "$SHA512SUM" = "$SHA512FILE" ]
 	then
diff --git a/rip_sources.sh b/rip_sources.sh
index e747a59..4c4c142 100755
--- a/rip_sources.sh
+++ b/rip_sources.sh
@@ -13,12 +13,6 @@ x_rewise()
 	rewise -x "./_tmp/$1" "$1"
 }
 
-sz_extract()
-{
-	7z x "$1"
-}
-
-
 # clean up
 if [ -d "./_tmp" ]
 then
@@ -31,8 +25,9 @@ x_rewise "hluplink.exe"
 x_rewise "hl1110.exe"
 x_rewise "opfordemofull.exe"
 x_rewise "hl_sdk_v23.exe"
+x_rewise "of1108.exe"
 x_rewise "steaminstall_halflife.exe"
-#x_rewise "steaminstall_opfor.exe"
+x_rewise "steaminstall_opfor.exe"
 
 mkdir -p "./_tmp/hluplink-pak0"
 pakextract -o "./_tmp/hluplink-pak0" "./_tmp/hluplink.exe/MAINDIR/valve/pak0.PAK"
@@ -40,19 +35,22 @@ pakextract -o "./_tmp/hluplink-pak0" "./_tmp/hluplink.exe/MAINDIR/valve/pak0.PAK
 mkdir -p "./_tmp/opfordemofull-pak0"
 pakextract -o "./_tmp/opfordemofull-pak0" "./_tmp/opfordemofull.exe/MAINDIR/valve/pak0.PAK"
 
+mkdir -p "./_tmp/opfordemofull-gbpak0"
+pakextract -o "./_tmp/opfordemofull-gbpak0" "./_tmp/opfordemofull.exe/MAINDIR/gearbox/pak0.PAK"
+
 mkdir -p "./_tmp/half-life.gcf"
 hlextract -p "./_tmp/steaminstall_halflife.exe/MAINDIR/SteamApps/half-life.gcf" -d "./_tmp/half-life.gcf" -e "root/valve/"
 
-#mkdir -p "./_tmp/opposing force.gcf"
-#hlextract -p "./_tmp/steaminstall_opfor.exe/MAINDIR/SteamApps/opposing force.gcf" -d "./_tmp/opposing force.gcf" -e "root/gearbox/"
+mkdir -p "./_tmp/opposing force.gcf"
+hlextract -p "./_tmp/steaminstall_opfor.exe/MAINDIR/SteamApps/opposing force.gcf" -d "./_tmp/opposing force.gcf" -e "root/gearbox/"
 
 ./ccase.sh -r "./_tmp"
 
 # if anything goes wrong here, it's probably imagemagick messing with the image
-if [ ! -x "$(command -v magick)" ]; then
-	convert "./_tmp/hluplink-pak0/gfx/shell/btns_main.bmp" -compress none -crop 156x4836+0+0 BMP3:"./_tmp/btns_main.bmp"
-else
-	magick "./_tmp/hluplink-pak0/gfx/shell/btns_main.bmp" -compress none -crop 156x4836+0+0 BMP3:"./_tmp/btns_main.bmp"
-fi
+convert "./_tmp/hluplink-pak0/gfx/shell/btns_main.bmp" -compress none -crop 156x4836+0+0 BMP3:"./_tmp/hluplink-pak0/btns_main.bmp"
+convert "./_tmp/of1108.exe/maindir/gearbox/gfx/shell/btns_main.bmp" -compress none -crop 156x5382+0+0 BMP3:"./_tmp/of1108.exe/btns_main.bmp"
 
-bmpfix "./_tmp/hl1110.exe/maindir/valve/models/player/hgrunt/hgrunt.bmp"
\ No newline at end of file
+bmpfix "./_tmp/hl1110.exe/maindir/valve/models/player/hgrunt/hgrunt.bmp"
+
+sed -i '/slot6,/d' "./_tmp/opfordemofull-pak0/gfx/shell/kb_act.lst"
+sed -i '/slot7,/d' "./_tmp/opfordemofull-pak0/gfx/shell/kb_act.lst"
\ No newline at end of file
diff --git a/start.sh b/start.sh
index 6b9552d..69d44d8 100755
--- a/start.sh
+++ b/start.sh
@@ -2,24 +2,35 @@
 set -e
 
 # some sanity checks before we continue
-if [ ! -x "$(command -v make)" ]; then
+if [ ! -x "$(command -v make)" ]
+then
 	echo "make not found. Please install GNU make."
 	exit 2
 fi
 
-if [ ! -x "$(command -v cc)" ]; then
+if [ ! -x "$(command -v cc)" ]
+then
 	echo "cc not found. Please install a C compiler."
 	exit 2
 fi
 
-if [ ! -x "$(command -v wget)" ]; then
+if [ ! -x "$(command -v wget)" ]
+then
 	echo "wget not found. Please install wget."
 	exit 2
 fi
 
-if [ ! -x "$(command -v magick)" ]; then
-	if [ ! -x "$(command -v convert)" ]; then
-		echo "magick/convert not found. Please install ImageMagick."
+if [ ! -x "$(command -v convert)" ]
+then
+	echo "magick/convert not found. Please install ImageMagick."
+	exit 2
+fi
+
+if [ ! -x "$(command -v sha512sum)" ]
+then
+	if [ ! -x "$(command -v sha512)" ]
+	then
+		echo "sha512 or sha512sum not found."
 		exit 2
 	fi
 fi