diff --git a/.gitignore b/.gitignore
index c7172ea..02f577c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,14 +1,19 @@
 orig
 *.IMG
 real-ld
-objcopy
-objdump
 *.o
 *.sw?
 coffsyrup
 123
-ld
 binutils-*
+as
+objcopy
+objdump
+ld
+gzip-*
+gzip
+gunzip
+zcat
 drawtest
 *.a
 keymap/keymap
diff --git a/Makefile b/Makefile
index 04643d4..5976529 100644
--- a/Makefile
+++ b/Makefile
@@ -79,21 +79,34 @@ distclean: clean
 	./extract.sh clean
 
 install: all
-	install -Dm 755 "bin/123" "$(prefix)/bin/123"
-	install -Dm 644 "share/man/man1/123.1" "$(prefix)/share/man/man1/123.1"
-	install -Dm 644 "share/lotus/etc/l123set.cf" "$(prefix)/share/lotus/etc/l123set.cf"
-	find "share/lotus/keymaps" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	install -Dm 644 "share/lotus/123.v10/sysV386/lotus.bcf" "$(prefix)/share/lotus/123.v10/sysV386/lotus.bcf"
-	install -Dm 644 "share/lotus/123.v10/sysV386/lib/wyse50-lts123" "$(prefix)/share/lotus/123.v10/sysV386/lib/wyse50-lts123"
-	find "share/lotus/123.v10/cbd" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/fonts" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/hlp" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/keymaps" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/pbd" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/ri" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
-	find "share/lotus/123.v10/smpfiles" -type f -exec install -Dm 644 {} "$(prefix)/{}" \;
+	install -m 0755 -d "$(prefix)/bin"
+	install -m 0755 "bin/123" "$(prefix)/bin/123"
+	install -m 0755 -d "$(prefix)/share/man/man1"
+	install -m 0644 "share/man/man1/123.1" "$(prefix)/share/man/man1/123.1"
+	install -m 0755 -d "$(prefix)/share/lotus/etc"
+	install -m 0644 "share/lotus/etc/l123set.cf" "$(prefix)/share/lotus/etc/l123set.cf"
+	find "share/lotus/keymaps" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/keymaps" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	install -m 0755 -d "$(prefix)/share/lotus/123.v10/sysV386"
+	install -m 0644 "share/lotus/123.v10/sysV386/lotus.bcf" "$(prefix)/share/lotus/123.v10/sysV386/lotus.bcf"
+	install -m 0755 -d "$(prefix)/share/lotus/123.v10/sysV386/lib"
+	install -m 0644 "share/lotus/123.v10/sysV386/lib/wyse50-lts123" "$(prefix)/share/lotus/123.v10/sysV386/lib/wyse50-lts123"
+	find "share/lotus/123.v10/cbd" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/cbd" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/fonts" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/fonts" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/hlp" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/hlp" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/keymaps" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/keymaps" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/pbd" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/pbd" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/ri" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/ri" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
+	find "share/lotus/123.v10/smpfiles" -type d -exec install -m 0755 -d "$(prefix)/{}" \;
+	find "share/lotus/123.v10/smpfiles" -type f -exec install -m 0644 {} "$(prefix)/{}" \;
 
 uninstall:
-	$(RM) "$(prefix)/bin/123"
-	$(RM) "$(prefix)/share/man/man1/123.1"
-	$(RM) -r "$(prefix)/share/lotus"
+	rm -f "$(prefix)/bin/123"
+	rm -f "$(prefix)/share/man/man1/123.1"
+	rm -rf "$(prefix)/share/lotus"
diff --git a/binutils.sh b/binutils.sh
index d6b642d..6f0cc47 100755
--- a/binutils.sh
+++ b/binutils.sh
@@ -4,55 +4,55 @@ BINUTILS_DL="https://ftp.gnu.org/gnu/binutils"
 BINUTILS_XZ="binutils-2.38.tar.xz"
 BINUTILS_DIR="$(basename $BINUTILS_XZ .tar.xz)"
 BINUTILS_URL="$BINUTILS_DL/$BINUTILS_XZ"
-ORIG_DIR="$(pwd)"
+ORIGIN_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
 
-# Dont continue on error.
-set -e
+# Make sure we have GNU make
+. "$ORIGIN_DIR/detect-gnu-make.sh"
 
 # Help text.
 if [ "$1" = '-h' ]; then
-   echo >&2 "Usage: $0 [clean]"
-   echo >&2
-   echo >&2 'Specify "clean" to remove binutils, otherwise it will be downloaded and built.'
-   exit 1
+    echo >&2 "Usage: $0 [clean]"
+    echo >&2
+    echo >&2 'Specify "clean" to remove binutils, otherwise it will be downloaded and built.'
+    exit 1
 fi
 
 # Optional cleanup if requested.
 if [ "$1" = 'clean' ]; then
-   rm -fv objcopy objdump ld "$BINUTILS_XZ"
-   rm -rfv "$BINUTILS_DIR"
-   exit
+    rm -fv "$ORIGIN_DIR/objcopy" "$ORIGIN_DIR/objdump" "$ORIGIN_DIR/ld" "$ORIGIN_DIR/as"
+    rm -rf "$BINUTILS_DIR"
+    rm -fv "$ORIGIN_DIR/$BINUTILS_XZ"
+    exit
 fi
 
 # Download binutils.
 if [ ! -f "$BINUTILS_XZ" ]; then
-   wget "$BINUTILS_URL"
+    wget "$BINUTILS_URL"
 fi
 
 # Extract binutils.
 if [ ! -d "$BINUTILS_DIR" ]; then
-   tar xf "$BINUTILS_XZ"
+    xzcat "$BINUTILS_XZ" | tar xf -
 fi
 
 # Compile binutils.
 if [ ! -x "$BINUTILS_DIR/binutils/objcopy" ]; then
-   cd "$BINUTILS_DIR"
-   ./configure --enable-targets=i386-pc-elf32 \
-               --disable-gas                  \
-               --disable-libctf               \
-               --disable-plugins              \
-               --disable-gprof                \
-               --enable-compressed-debug-sections=none
-
-   make all-ld -j$(nproc) MAKEINFO=true
+    cd "$BINUTILS_DIR" && \
+    ./configure --enable-targets=i386-pc-elf32 \
+                --disable-libctf \
+                --disable-plugins \
+                --disable-gprof \
+                --enable-compressed-debug-sections=none && \
+    "$gnu_make" all-ld all-gas MAKEINFO=true
+    cd "$ORIGIN_DIR"
 fi
 
 # Copy compiled binaries to working directory.
 copy() {
-   test ! -x "$2" && cp -v "$1" "$2"
+    test ! -x "$2" && cp -v "$1" "$2"
 }
 
-cd "$ORIG_DIR"
-copy "$BINUTILS_DIR/binutils/objcopy" objcopy
-copy "$BINUTILS_DIR/binutils/objdump" objdump
-copy "$BINUTILS_DIR/ld/ld-new" ld
+copy "$BINUTILS_DIR/binutils/objcopy" "$ORIGIN_DIR/objcopy"
+copy "$BINUTILS_DIR/binutils/objdump" "$ORIGIN_DIR/objdump"
+copy "$BINUTILS_DIR/ld/ld-new" "$ORIGIN_DIR/ld"
+copy "$BINUTILS_DIR/gas/as-new" "$ORIGIN_DIR/as"
diff --git a/detect-gnu-make.sh b/detect-gnu-make.sh
new file mode 100644
index 0000000..fdff300
--- /dev/null
+++ b/detect-gnu-make.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+gnu_make="$(command -v make 2>/dev/null)"
+if command -v gmake >/dev/null 2>&1; then
+    gnu_make="$(command -v gmake)"
+fi
+if [ -z "$gnu_make" -o "$("$gnu_make" --version 2>/dev/null | head -n 1 | cut -c-3)" != "GNU" ]; then
+    echo >&2 "Could not find GNU make in PATH"
+    exit 1
+fi
diff --git a/extract.sh b/extract.sh
index 0a419bd..08ee3d9 100755
--- a/extract.sh
+++ b/extract.sh
@@ -13,7 +13,7 @@ CPIO="$(command -v cpio)"
 TAR="$(command -v tar)"
 
 if [ "$1" = 'clean' ]; then
-    rm -rfv "${ROOT}" "${ORIG}" "${ETC}"
+    rm -rf "${ROOT}" "${ORIG}" "${ETC}"
     exit
 fi
 
@@ -50,7 +50,6 @@ echo '==> Reconstructing object file'
 
 if ! cat "${LOTUS}"/sysV386/lib/123.o.z_1 "${LOTUS}"/sysV386/lib/123.o.z_2 | zcat > "${ORIG}/123.o"; then
     echo >&2 'Failed to decompress object files.'
-
     echo >&2 'If you see the message "code out of range", gzip is too old.'
     echo >&2 'You can try running ./gzip.sh to build a recent gzip that is known to work.'
     exit 1
@@ -63,10 +62,12 @@ echo '==> Uncompressing and copying remaining object files'
 cp "${LOTUS}"/sysV386/lib/*.o "${ORIG}/"
 
 echo '==> Copying the banner template over'
-install -vDm644 "${ROOT}/usr/tmp/lotus_install/123/banner" "${LOTUS}/ri/USA-English/123ban.ri"
+install -m 0644 "${ROOT}/usr/tmp/lotus_install/123/banner" "${LOTUS}/ri/USA-English/123ban.ri"
 
 echo '==> Copying default config file'
-install -vDm644 l123set.cf "${ETC}/l123set.cf"
+install -m 0755 -d "${ETC}"
+install -m 0644 "l123set.cf" "${ETC}/l123set.cf"
 
 echo '==> Copying man page'
-install -vDm644 "${ROOT}/lotus/man/man1/123.1" "${ROOT}/man/man1/123.1"
+install -m 0755 -d "${ROOT}/man/man1"
+install -m 0644 "${ROOT}/lotus/man/man1/123.1" "${ROOT}/man/man1/123.1"
diff --git a/gzip.sh b/gzip.sh
index d066fe9..548747c 100755
--- a/gzip.sh
+++ b/gzip.sh
@@ -6,41 +6,41 @@ GZIP_DL="https://ftp.gnu.org/gnu/gzip"
 GZIP_XZ="gzip-1.12.tar.xz"
 GZIP_DIR="$(basename $GZIP_XZ .tar.xz)"
 GZIP_URL="$GZIP_DL/$GZIP_XZ"
-ORIG_DIR="$(pwd)"
+ORIGIN_DIR="$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)"
 
-# Dont continue on error.
-set -e
+# Make sure we have GNU make
+. "$ORIGIN_DIR/detect-gnu-make.sh"
 
 # Help text.
 if [ "$1" = '-h' ]; then
-   echo >&2 "Usage: $0 [clean]"
-   echo >&2
-   echo >&2 'Specify "clean" to remove gzip, otherwise it will be downloaded and built.'
-   exit 1
+    echo >&2 "Usage: $0 [clean]"
+    echo >&2
+    echo >&2 'Specify "clean" to remove gzip, otherwise it will be downloaded and built.'
+    exit 1
 fi
 
 # Optional cleanup if requested.
 if [ "$1" = 'clean' ]; then
-   rm -fv gzip gunzip zcat "$GZIP_XZ"
-   rm -rfv "$GZIP_DIR"
-   exit
+    rm -fv "$ORIGIN_DIR/gzip" "$ORIGIN_DIR/gunzip" "$ORIGIN_DIR/zcat"
+    rm -rf "$GZIP_DIR"
+    rm -fv "$ORIGIN_DIR/$GZIP_XZ"
+    exit
 fi
 
 # Download gzip.
 if [ ! -f "$GZIP_XZ" ]; then
-   wget "$GZIP_URL"
+    wget "$GZIP_URL"
 fi
 
 # Extract gzip.
 if [ ! -d "$GZIP_DIR" ]; then
-   tar xf "$GZIP_XZ"
+    xzcat "$GZIP_XZ" | tar xf -
 fi
 
 # Compile gzip.
 if [ ! -x "$GZIP_DIR/gzip" ]; then
-   cd "$GZIP_DIR"
-   ./configure
-   make -j$(nproc)
+   cd "$GZIP_DIR" && ./configure && "$gnu_make"
+   cd "$ORIGIN_DIR"
 fi
 
 # Copy compiled binaries to working directory.
@@ -48,7 +48,6 @@ copy() {
    test ! -x "$2" && cp -v "$1" "$2"
 }
 
-cd "$ORIG_DIR"
-copy "$GZIP_DIR/gzip" gzip
-copy "$GZIP_DIR/gunzip" gunzip
-copy "$GZIP_DIR/zcat" zcat
+copy "$GZIP_DIR/gzip" "$ORIGIN_DIR/gzip"
+copy "$GZIP_DIR/gunzip" "$ORIGIN_DIR/gunzip"
+copy "$GZIP_DIR/zcat" "$ORIGIN_DIR/zcat"