diff --git a/.gitignore b/.gitignore
index 993b71b6..9f8b23bd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,9 @@
 # Prevent overwriting user config
 config.yaml
 
+# Ignore tools directories
+tools/local
+
 # Ignore generated documents but keep the docs directory
 docs/*
 !docs/.gitkeep
diff --git a/build-docs b/build-docs
index 07fc7091..e115ef94 100755
--- a/build-docs
+++ b/build-docs
@@ -2,16 +2,16 @@
 
 # vars
 SELF="${BASH_SOURCE[0]}"
-BASE_DIR=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd -P)
-BASE_DIR="${BASE_DIR:-$(pwd)}"
-CONFIG="${BASE_DIR}/config.yaml"
-DOCS_DIR="${BASE_DIR}/docs"
-SOURCE_DIR="${BASE_DIR}/source"
-TEMPLATE_DIR="${BASE_DIR}/templates"
-TOOLS_DIR="${BASE_DIR}/tools"
+SELF_DIR=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd -P)
+SELF_DIR="${SELF_DIR:-$(pwd)}"
+CONFIG="${SELF_DIR}/config.yaml"
+DOCS_DIR="${SELF_DIR}/docs"
+SOURCE_DIR="${SELF_DIR}/source"
+TEMPLATE_DIR="${SELF_DIR}/templates"
+TOOLS_BIN="${SELF_DIR}/tools/local/bin"
 
 # dependencies
-MARKDOWN="${BASE_DIR}/tools/discount/markdown"
+MARKDOWN="${TOOLS_BIN}/markdown"
 DEPS=("${MARKDOWN}")
 
 # optional dependencies
@@ -213,7 +213,7 @@ function build_source {
 }
 
 # base directory (absolute)
-cd "${BASE_DIR}"
+cd "${SELF_DIR}"
 
 # check deps
 check_dependencies "${DEPS[@]}" || exit 1
@@ -293,7 +293,7 @@ else
         done
         cd "${SOURCE_DIR}"
     done
-    cd "${BASE_DIR}"
+    cd "${SELF_DIR}"
 
     # sources
     SOURCES=($(find "${DOCS_DIR}" | sed 's/^\.\///' | grep -i '.markdown'))
diff --git a/build-tools b/build-tools
index b5bd0675..87dd786b 100755
--- a/build-tools
+++ b/build-tools
@@ -2,41 +2,75 @@
 
 # vars
 SELF="${BASH_SOURCE[0]}"
-BASE_DIR=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd -P)
-BASE_DIR="${BASE_DIR:-$(pwd)}"
-TOOLS_DIR="${BASE_DIR}/tools"
-SYSTEM_NAME=$(uname -s)
+SELF_DIR=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd -P)
+SELF_DIR="${SELF_DIR:-$(pwd)}"
+TOOLS_DIR="${SELF_DIR}/tools"
+BUILD_DIR="${TOOLS_DIR}/local/build"
+INSTALL_DIR="${TOOLS_DIR}/local"
+TOOLS=('discount' 'zlib' 'libpng' 'pngquant' 'zopfli')
 
 # discount
 function build_discount {
-    cd "${TOOLS_DIR}/discount"
-    if make clean; then
-        make distclean
-    fi
-    if [[ "${SYSTEM_NAME}" == "Darwin" ]]; then
-        ./configure.sh --mandir=/usr/local/share/man
-    else
-        ./configure.sh
-    fi
-    make
+    ./configure.sh --prefix="${INSTALL_DIR}" || return 1
+    make || return 1
+    make install || return 1
 }
 
-# base directory (absolute)
-cd "${BASE_DIR}"
+# zlib
+function build_zlib {
+    ./configure --static --prefix="${INSTALL_DIR}" || return 1
+    make || return 1
+    make install || return 1
+    rm -f "${INSTALL_DIR}/lib/libz*.dylib"
+}
+
+# libpng
+function build_libpng {
+    rm -rf Makefile.in aclocal.m4 automate.cache/ compile config.guess config.h.in config.sub configure depcomp install-sh ltmain.sh missing scripts/libtool.m4 scripts/ltoptions.m4 scripts/ltsugar.m4 scripts/ltversion.m4 scripts/lt~obsolete.m4 test-driver || return 1
+    ./autogen.sh || return 1
+    CFLAGS="-I${INSTALL_DIR}/include" CPPFLAGS="-I${INSTALL_DIR}/include" LDFLAGS="-L${INSTALL_DIR}/lib -lz" ./configure --with-zlib-prefix="${INSTALL_DIR}" --prefix="${INSTALL_DIR}" --disable-shared --enable-static || return 1
+    make || return 1
+    make install || return 1
+}
+
+# pngquant
+function build_pngquant {
+    ./configure --extra-cflags="-I${INSTALL_DIR}/include" --extra-ldflags="-L${INSTALL_DIR}/lib -lz" --prefix="${INSTALL_DIR}" --with-libpng="${INSTALL_DIR}" --without-cocoa || return 1
+    sed -i.sedbak -e 's:-L/usr/lib -lz::g' config.mk || return 1
+    rm -f config.mk.sedbak
+    make || return 1
+    make install || return 1
+}
+
+# zopfli
+function build_zopfli {
+    make zopfli zopflipng || return 1
+    cp zopfli zopflipng "${INSTALL_DIR}/bin" || return 1
+}
 
 # main
-cd "${TOOLS_DIR}"
+rm -rf "${INSTALL_DIR}"
+rm -rf "${BUILD_DIR}"
+mkdir -p "${BUILD_DIR}"
+cd "${BUILD_DIR}"
 ERROR=false
-for TOOL in */; do
-    TOOL="${TOOL%/}"  # strip trailing slash
+echo "Building:"
+for TOOL in "${TOOLS[@]}"; do
+    echo "  ${TOOL}"
+    cp -R "${TOOLS_DIR}/${TOOL}" "${BUILD_DIR}/"
+    rm -rf "${BUILD_DIR}/${TOOL}/.git"
+    cd "${BUILD_DIR}/${TOOL}"
     if ! build_${TOOL} >/dev/null 2>&1; then
         ERROR=true
-        echo "Error: Unable to build tool '${TOOL}'." >&2
+        echo "Unable to build tool: ${TOOL}" >&2
+        break
     fi
 done
+rm -rf "${BUILD_DIR}"
 
 # done
 if [[ "${ERROR}" == true ]]; then
     exit 1
 fi
+echo "Complete."
 exit 0