diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 000000000000..cda801d9a879
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,93 @@
+name: "Build"
+
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+
+env:
+  BUILD_CERTIFICATE_BASE64: ${{ secrets.OSX_BUILD_CERTIFICATE_BASE64 }}
+  P12_PASSWORD: ${{ secrets.OSX_P12_PASSWORD }}
+  KEYCHAIN_PASSWORD: ${{ secrets.OSX_KEYCHAIN_PASSWORD }}
+  CODESIGN_CERT: ${{ secrets.OSX_CODESIGN_CERT }}
+  APPLE_ID_USER: ${{ secrets.OSX_APPLE_ID_USER }}
+  APPLE_ID_PASSWORD: ${{ secrets.OSX_APPLE_ID_PASSWORD }}
+  APPLE_ID_PROVIDER_SHORT_NAME: ${{ secrets.OSX_APPLE_ID_PROVIDER_SHORT_NAME }}
+
+jobs:
+  macos:
+    runs-on: macos-10.15
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+      - name: Install the Apple certificate
+        run: |
+          set -e
+          # create variables
+          CERTIFICATE_PATH=$RUNNER_TEMP/build_certificate.p12
+          KEYCHAIN_PATH=$RUNNER_TEMP/app-signing.keychain-db
+
+          # import certificate and provisioning profile from secrets
+          echo -n "$BUILD_CERTIFICATE_BASE64" | base64 --decode --output $CERTIFICATE_PATH
+
+          # create temporary keychain
+          security create-keychain -p "$KEYCHAIN_PASSWORD" $KEYCHAIN_PATH
+          security set-keychain-settings -lut 21600 $KEYCHAIN_PATH
+          security unlock-keychain -p "$KEYCHAIN_PASSWORD" $KEYCHAIN_PATH
+
+          # import certificate to keychain
+          security import $CERTIFICATE_PATH -P $P12_PASSWORD -A -t cert -f pkcs12 -k $KEYCHAIN_PATH
+          security list-keychain -d user -s $KEYCHAIN_PATH
+      - name: Build app
+        run: ./contrib/osx/make_osx $CODESIGN_CERT
+      - name: 'Upload Artifact'
+        uses: actions/upload-artifact@v2
+        with:
+          name: artifact-macos
+          path: dist/*.dmg
+          
+  windows:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+      - name: Builder image
+        env:
+          TARGET_OS: Windows
+        run: docker build --no-cache -t electrum-wine-builder-img ./contrib/build-wine/
+      - name: Compile Windows binary
+        env:
+          TARGET_OS: Windows
+        run: docker run --name electrum-wine-builder-cont -v $PWD:/opt/wine64/drive_c/electrum --rm --workdir /opt/wine64/drive_c/electrum/contrib/build-wine electrum-wine-builder-img ./build.sh
+      - name: 'Upload Artifact'
+        uses: actions/upload-artifact@v2
+        with:
+          name: artifact-windows
+          path: contrib/build-wine/dist/*.exe
+          if-no-files-found: error
+          retention-days: 7
+
+  appimage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+      - name: Builder image
+        run: docker build --no-cache -t electrum-appimage-builder-img ./contrib/build-linux/appimage/
+      - name: Compile Linux AppImage
+        run: docker run --name electrum-appimage-builder-cont -v $PWD:/opt/electrum --rm --workdir /opt/electrum/contrib/build-linux/appimage electrum-appimage-builder-img ./build.sh
+      - name: 'Upload Artifact'
+        uses: actions/upload-artifact@v2
+        with:
+          name: artifact-appimage
+          path: dist/*.AppImage
+          if-no-files-found: error
+          retention-days: 7
diff --git a/.gitignore b/.gitignore
index 8f0c77ef1dca..a9d62b38f7ad 100644
--- a/.gitignore
+++ b/.gitignore
@@ -43,6 +43,20 @@ venv
 .DS_Store
 
 # Temporary bulds files
+contrib/secp256k1
 contrib/osx/libsecp256k1.0.dylib
 contrib/osx/libusb-1.0.dylib
+electrum/libsecp256k1-0.dll
+electrum/libsecp256k1.so.0
 prebuilt_qr/
+
+# generated locale's
+contrib/deterministic-build/electrum-locale
+electrum/es_ES
+electrum/id_ID
+electrum/ja_JP
+electrum/ko_KR
+electrum/pt_PT
+electrum/tr_TR
+electrum/vi_VN
+electrum/zh_CN
diff --git a/contrib/build-linux/appimage/Dockerfile b/contrib/build-linux/appimage/Dockerfile
index 7003235a2694..f4afb1e9fd97 100644
--- a/contrib/build-linux/appimage/Dockerfile
+++ b/contrib/build-linux/appimage/Dockerfile
@@ -21,7 +21,7 @@ RUN apt-get update -q && \
         libusb-1.0-0-dev=2:1.0.20-1 \
         libudev-dev=229-4ubuntu21.31 \
         gettext=0.19.7-2ubuntu3.1 \
-        libzbar0=0.10+doc-10ubuntu1  \
+        libzbar0=0.10+doc-10ubuntu1 \
         libdbus-1-3=1.10.6-1ubuntu3.6 \
         libxkbcommon-x11-0=0.5.0-1ubuntu2.1 \
         libxcb-util1=0.4.0-0ubuntu3 \
diff --git a/contrib/build-wine/Dockerfile b/contrib/build-wine/Dockerfile
index 60464e2cde4e..27e742c32da7 100644
--- a/contrib/build-wine/Dockerfile
+++ b/contrib/build-wine/Dockerfile
@@ -1,4 +1,3 @@
-
 FROM ubuntu:18.04@sha256:b58746c8a89938b8c9f5b77de3b8cf1fe78210c696ab03a1442e235eea65d84f
 
 ENV LC_ALL=C.UTF-8 LANG=C.UTF-8
@@ -7,14 +6,14 @@ RUN dpkg --add-architecture i386 && \
     apt-get update -q && \
     apt-get install -qy \
         wget=1.19.4-1ubuntu2.2 \
-        gnupg2=2.2.4-1ubuntu1.4 \
-        dirmngr=2.2.4-1ubuntu1.4 \
-        python3-software-properties=0.96.24.32.1 \
-        software-properties-common=0.96.24.32.1
+        gnupg2=2.2.4-1ubuntu1.5 \
+        dirmngr=2.2.4-1ubuntu1.5 \
+        python3-software-properties=0.96.24.32.14 \
+        software-properties-common=0.96.24.32.14
 
 RUN apt-get update -q && \
         apt-get install -qy \
-        git=1:2.17.1-1ubuntu0.9 \
+        git=1:2.17.1-1ubuntu0.11 \
         p7zip-full=16.02+dfsg-6 \
         make=4.1-9.1ubuntu1 \
         mingw-w64=5.0.3-1 \
@@ -24,7 +23,7 @@ RUN apt-get update -q && \
         autopoint=0.19.8.1-6ubuntu0.3 \
         autoconf=2.69-11 \
         libtool=2.4.6-2 \
-        gettext=0.19.8.1-6
+        gettext=0.19.8.1-6ubuntu0.3
 
 RUN wget -nc https://dl.winehq.org/wine-builds/Release.key && \
         echo "c51bcb8cc4a12abfbd7c7660eaf90f49674d15e222c262f27e6c96429111b822 Release.key" | sha256sum -c - && \
diff --git a/contrib/build-wine/build-electrum-git.sh b/contrib/build-wine/build-electrum-git.sh
index e7ec10155752..fff7f9677149 100755
--- a/contrib/build-wine/build-electrum-git.sh
+++ b/contrib/build-wine/build-electrum-git.sh
@@ -11,6 +11,7 @@ export PYTHONHASHSEED=22
 PYHOME=c:/python3
 PYTHON="wine $PYHOME/python.exe -OO -B"
 
+git config --global --add safe.directory $WINEPREFIX/drive_c/electrum
 
 # Let's begin!
 set -e
@@ -60,7 +61,7 @@ rm -rf dist/
 
 # build standalone and portable versions
 info "Running pyinstaller..."
-wine "$PYHOME/scripts/pyinstaller.exe" --noconfirm --ascii --clean --name $NAME_ROOT-$VERSION -w deterministic.spec
+wine "$PYHOME/scripts/pyinstaller.exe" --noconfirm --ascii --clean deterministic.spec
 
 # set timestamps in dist, in order to make the installer reproducible
 pushd dist
diff --git a/contrib/build-wine/deterministic.spec b/contrib/build-wine/deterministic.spec
index c4db5367fb30..176f772f7560 100644
--- a/contrib/build-wine/deterministic.spec
+++ b/contrib/build-wine/deterministic.spec
@@ -3,12 +3,9 @@
 from PyInstaller.utils.hooks import collect_data_files, collect_submodules, collect_dynamic_libs
 
 import sys
-for i, x in enumerate(sys.argv):
-    if x == '--name':
-        cmdline_name = sys.argv[i+1]
-        break
-else:
-    raise Exception('no name')
+for i, x in enumerate(sys.argv):import os
+
+cmdline_name = str(os.environ['NAME_ROOT']+"-"+os.environ['VERSION'])
 
 PYHOME = 'c:/python3'
 
diff --git a/contrib/build-wine/prepare-wine.sh b/contrib/build-wine/prepare-wine.sh
index ef8ea1fab540..1b1ce8e53600 100755
--- a/contrib/build-wine/prepare-wine.sh
+++ b/contrib/build-wine/prepare-wine.sh
@@ -123,6 +123,6 @@ info "Building PyInstaller."
     fi
 ) || fail "PyInstaller build failed"
 info "Installing PyInstaller."
-$PYTHON -m pip install --no-dependencies --no-warn-script-location ./pyinstaller
+$PYTHON -m pip install pyinstaller #--no-dependencies --no-warn-script-location ./pyinstaller
 
 info "Wine is configured."
diff --git a/contrib/make_libusb.sh b/contrib/make_libusb.sh
new file mode 100755
index 000000000000..20e3f27c375e
--- /dev/null
+++ b/contrib/make_libusb.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+
+LIBUSB_VERSION="c6a35c56016ea2ab2f19115d2ea1e85e0edae155"
+# ^ tag v1.0.24
+
+set -e
+
+. $(dirname "$0")/build_tools_util.sh || (echo "Could not source build_tools_util.sh" && exit 1)
+
+here=$(dirname $(realpath "$0" 2> /dev/null || grealpath "$0"))
+CONTRIB="$here"
+PROJECT_ROOT="$CONTRIB/.."
+
+pkgname="libusb"
+info "Building $pkgname..."
+
+(
+    cd $CONTRIB
+    if [ ! -d libusb ]; then
+        git clone https://github.com/libusb/libusb.git
+    fi
+    cd libusb
+    if ! $(git cat-file -e ${LIBUSB_VERSION}) ; then
+        info "Could not find requested version $LIBUSB_VERSION in local clone; fetching..."
+        git fetch --all
+    fi
+    git reset --hard
+    git clean -dfxq
+    git checkout "${LIBUSB_VERSION}^{commit}"
+
+    if [ "$BUILD_TYPE" = "wine" ] ; then
+        echo "libusb_1_0_la_LDFLAGS += -Wc,-static" >> libusb/Makefile.am
+    fi
+    ./bootstrap.sh || fail "Could not bootstrap libusb"
+    if ! [ -r config.status ] ; then
+        if [ "$BUILD_TYPE" = "wine" ] ; then
+            # windows target
+            LDFLAGS="-Wl,--no-insert-timestamp"
+        elif [ $(uname) == "Darwin" ]; then
+            # macos target
+            LDFLAGS="-Wl -lm"
+        else
+            # linux target
+            LDFLAGS=""
+        fi
+        LDFLAGS="$LDFLAGS" ./configure \
+            $AUTOCONF_FLAGS \
+            || fail "Could not configure $pkgname. Please make sure you have a C compiler installed and try again."
+    fi
+    make -j4 || fail "Could not build $pkgname"
+    make install || fail "Could not install $pkgname"
+    . "$here/$pkgname/libusb/.libs/libusb-1.0.la"
+    host_strip "$here/$pkgname/libusb/.libs/$dlname"
+    TARGET_NAME="$dlname"
+    if [ $(uname) == "Darwin" ]; then  # on mac, dlname is "libusb-1.0.0.dylib"
+        TARGET_NAME="libusb-1.0.dylib"
+    fi
+    cp -fpv "$here/$pkgname/libusb/.libs/$dlname" "$PROJECT_ROOT/electrum/$TARGET_NAME" || fail "Could not copy the $pkgname binary to its destination"
+    info "$TARGET_NAME has been placed in the inner 'electrum' folder."
+    if [ -n "$DLL_TARGET_DIR" ] ; then
+        cp -fpv "$here/$pkgname/libusb/.libs/$dlname" "$DLL_TARGET_DIR/$TARGET_NAME" || fail "Could not copy the $pkgname binary to DLL_TARGET_DIR"
+    fi
+)
diff --git a/contrib/make_zbar.sh b/contrib/make_zbar.sh
new file mode 100755
index 000000000000..de60c68abd6e
--- /dev/null
+++ b/contrib/make_zbar.sh
@@ -0,0 +1,93 @@
+#!/bin/bash
+
+# This script can be used on Linux hosts to build native libzbar binaries.
+# sudo apt-get install pkg-config libx11-dev libx11-6 libv4l-dev libxv-dev libxext-dev libjpeg-dev
+#
+# It can also be used to cross-compile to Windows:
+# $ sudo apt-get install mingw-w64 mingw-w64-tools win-iconv-mingw-w64-dev
+# For a Windows x86 (32-bit) target, run:
+# $ GCC_TRIPLET_HOST="i686-w64-mingw32" BUILD_TYPE="wine" ./contrib/make_zbar.sh
+# Or for a Windows x86_64 (64-bit) target, run:
+# $ GCC_TRIPLET_HOST="x86_64-w64-mingw32" BUILD_TYPE="wine" ./contrib/make_zbar.sh
+
+ZBAR_VERSION="aac86d5f08d64ab4c3da78188eb622fa3cb07182"
+
+set -e
+
+. $(dirname "$0")/build_tools_util.sh || (echo "Could not source build_tools_util.sh" && exit 1)
+
+here=$(dirname $(realpath "$0" 2> /dev/null || grealpath "$0"))
+CONTRIB="$here"
+PROJECT_ROOT="$CONTRIB/.."
+
+pkgname="zbar"
+info "Building $pkgname..."
+
+(
+    cd $CONTRIB
+    if [ ! -d zbar ]; then
+        git clone https://github.com/mchehab/zbar.git
+    fi
+    cd zbar
+    if ! $(git cat-file -e ${ZBAR_VERSION}) ; then
+        info "Could not find requested version $ZBAR_VERSION in local clone; fetching..."
+        git fetch --all
+    fi
+    git reset --hard
+    git clean -dfxq
+    git checkout "${ZBAR_VERSION}^{commit}"
+
+    if [ "$BUILD_TYPE" = "wine" ] ; then
+        echo "libzbar_la_LDFLAGS += -Wc,-static" >> zbar/Makefile.am
+        echo "LDFLAGS += -Wc,-static" >> Makefile.am
+    fi
+    if ! [ -x configure ] ; then
+        autoreconf -vfi || fail "Could not run autoreconf for $pkgname. Please make sure you have automake and libtool installed, and try again."
+    fi
+    if ! [ -r config.status ] ; then
+        if [ "$BUILD_TYPE" = "wine" ] ; then
+            # windows target
+            AUTOCONF_FLAGS="$AUTOCONF_FLAGS \
+                --with-x=no \
+                --enable-video=yes \
+                --with-jpeg=no \
+                --with-directshow=yes \
+                --disable-dependency-tracking"
+        elif [ $(uname) == "Darwin" ]; then
+            # macos target
+            AUTOCONF_FLAGS="$AUTOCONF_FLAGS \
+                --with-x=no \
+                --enable-video=no \
+                --with-jpeg=no"
+        else
+            # linux target
+            AUTOCONF_FLAGS="$AUTOCONF_FLAGS \
+                --with-x=yes \
+                --enable-video=yes \
+                --with-jpeg=yes"
+        fi
+        ./configure \
+            $AUTOCONF_FLAGS \
+            --prefix="$here/$pkgname/dist" \
+            --enable-pthread=no \
+            --enable-doc=no \
+            --with-python=no \
+            --with-gtk=no \
+            --with-qt=no \
+            --with-java=no \
+            --with-imagemagick=no \
+            --with-dbus=no \
+            --enable-codes=qrcode \
+            --disable-static \
+            --enable-shared || fail "Could not configure $pkgname. Please make sure you have a C compiler installed and try again."
+    fi
+    make -j4 || fail "Could not build $pkgname"
+    make install || fail "Could not install $pkgname"
+    . "$here/$pkgname/dist/lib/libzbar.la"
+    host_strip "$here/$pkgname/dist/lib/$dlname"
+    cp -fpv "$here/$pkgname/dist/lib/$dlname" "$PROJECT_ROOT/electrum" || fail "Could not copy the $pkgname binary to its destination"
+    info "$dlname has been placed in the inner 'electrum' folder."
+    if [ -n "$DLL_TARGET_DIR" ] ; then
+        cp -fpv "$here/$pkgname/dist/lib/$dlname" "$DLL_TARGET_DIR" || fail "Could not copy the $pkgname binary to DLL_TARGET_DIR"
+    fi
+)
diff --git a/contrib/osx/make_osx b/contrib/osx/make_osx
index c193be963bb5..43f6e00d812a 100755
--- a/contrib/osx/make_osx
+++ b/contrib/osx/make_osx
@@ -14,6 +14,7 @@ export GCC_STRIP_BINARIES="1"
 
 CONTRIB_OSX="$(dirname "$(realpath "$0")")"
 CONTRIB="$CONTRIB_OSX/.."
+PROJECT_ROOT="$CONTRIB/.."
 ROOT_FOLDER="$CONTRIB/.."
 
 src_dir=$(dirname "$0")
@@ -114,18 +115,32 @@ info "generating locale"
     done
 ) || fail "failed generating locale"
 
+info "Installing some build-time deps for compilation..."
+brew install autoconf automake libtool gettext coreutils pkgconfig openssl
 
-info "Downloading libusb..."
-curl https://homebrew.bintray.com/bottles/libusb-1.0.23.high_sierra.bottle.tar.gz | \
-tar xz --directory "$BUILDDIR"
-cp "$BUILDDIR/libusb/1.0.23/lib/libusb-1.0.dylib" contrib/osx
-echo "caea266f3fc3982adc55d6cb8d9bad10f6e61f0c24ce5901aa1804618e08e14d  contrib/osx/libusb-1.0.dylib" | \
-    shasum -a 256 -c || fail "libusb checksum mismatched"
+if [ ! -f "$PROJECT_ROOT"/electrum/libsecp256k1.0.dylib ]; then
+    info "Building libsecp256k1 dylib..."
+    "$CONTRIB"/make_libsecp256k1.sh || fail "Could not build libsecp"
+else
+    info "Skipping libsecp256k1 build: reusing already built dylib."
+fi
+cp "$PROJECT_ROOT"/electrum/libsecp256k1.0.dylib "$CONTRIB"/osx
 
-info "Preparing for building libsecp256k1"
-brew install autoconf automake libtool
-"$CONTRIB"/make_libsecp256k1.sh || fail "Could not build libsecp"
-cp "$ROOT_FOLDER"/electrum/libsecp256k1.0.dylib contrib/osx
+if [ ! -f "$PROJECT_ROOT"/electrum/libzbar.0.dylib ]; then
+    info "Building ZBar dylib..."
+    "$CONTRIB"/make_zbar.sh || fail "Could not build ZBar dylib"
+else
+    info "Skipping ZBar build: reusing already built dylib."
+fi
+cp "$PROJECT_ROOT"/electrum/libzbar.0.dylib "$CONTRIB"/osx
+
+if [ ! -f "$PROJECT_ROOT"/electrum/libusb-1.0.dylib ]; then
+    info "Building libusb dylib..."
+    "$CONTRIB"/make_libusb.sh || fail "Could not build libusb dylib"
+else
+    info "Skipping libusb build: reusing already built dylib."
+fi
+cp "$PROJECT_ROOT"/electrum/libusb-1.0.dylib "$CONTRIB"/osx
 
 info "Building CalinsQRReader..."
 d=contrib/osx/CalinsQRReader