diff --git a/.appveyor.yml b/.appveyor.yml
index f2a5aa11b..d9acfa513 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -3,6 +3,8 @@ image: Visual Studio 2017
 
 environment:
   matrix:
+    - version: 3.9-rc
+      variant: windowsservercore-ltsc2016
     - version: 3.8
       variant: windowsservercore-ltsc2016
     - version: 3.7
diff --git a/.travis.yml b/.travis.yml
index e21e5d746..9606425f4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,10 @@ services: docker
 
 matrix:
   include:
+    - os: linux
+      env: VERSION=3.9-rc VARIANT=buster
+    - os: linux
+      env: VERSION=3.9-rc VARIANT=alpine3.10
     - os: linux
       env: VERSION=3.8 VARIANT=buster
     - os: linux
diff --git a/3.9-rc/alpine3.10/Dockerfile b/3.9-rc/alpine3.10/Dockerfile
new file mode 100644
index 000000000..ee735e9cd
--- /dev/null
+++ b/3.9-rc/alpine3.10/Dockerfile
@@ -0,0 +1,134 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "update.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM alpine:3.10
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# http://bugs.python.org/issue19846
+# > At the moment, setting "LANG=C" on a Linux system *fundamentally breaks Python 3*, and that's not OK.
+ENV LANG C.UTF-8
+
+# install ca-certificates so that HTTPS works consistently
+# other runtime dependencies for Python are installed later
+RUN apk add --no-cache ca-certificates
+
+ENV GPG_KEY E3FF2839C048B25C084DEBE9B26995E310250568
+ENV PYTHON_VERSION 3.9.0a1
+
+RUN set -ex \
+	&& apk add --no-cache --virtual .fetch-deps \
+		gnupg \
+		tar \
+		xz \
+	\
+	&& wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" \
+	&& wget -O python.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" \
+	&& export GNUPGHOME="$(mktemp -d)" \
+	&& gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$GPG_KEY" \
+	&& gpg --batch --verify python.tar.xz.asc python.tar.xz \
+	&& { command -v gpgconf > /dev/null && gpgconf --kill all || :; } \
+	&& rm -rf "$GNUPGHOME" python.tar.xz.asc \
+	&& mkdir -p /usr/src/python \
+	&& tar -xJC /usr/src/python --strip-components=1 -f python.tar.xz \
+	&& rm python.tar.xz \
+	\
+	&& apk add --no-cache --virtual .build-deps  \
+		bzip2-dev \
+		coreutils \
+		dpkg-dev dpkg \
+		expat-dev \
+		findutils \
+		gcc \
+		gdbm-dev \
+		libc-dev \
+		libffi-dev \
+		libnsl-dev \
+		libtirpc-dev \
+		linux-headers \
+		make \
+		ncurses-dev \
+		openssl-dev \
+		pax-utils \
+		readline-dev \
+		sqlite-dev \
+		tcl-dev \
+		tk \
+		tk-dev \
+		util-linux-dev \
+		xz-dev \
+		zlib-dev \
+# add build deps before removing fetch deps in case there's overlap
+	&& apk del .fetch-deps \
+	\
+	&& cd /usr/src/python \
+	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
+	&& ./configure \
+		--build="$gnuArch" \
+		--enable-loadable-sqlite-extensions \
+		--enable-optimizations \
+		--enable-shared \
+		--with-system-expat \
+		--with-system-ffi \
+		--without-ensurepip \
+	&& make -j "$(nproc)" \
+# set thread stack size to 1MB so we don't segfault before we hit sys.getrecursionlimit()
+# https://github.com/alpinelinux/aports/commit/2026e1259422d4e0cf92391ca2d3844356c649d0
+		EXTRA_CFLAGS="-DTHREAD_STACK_SIZE=0x100000" \
+	&& make install \
+	\
+	&& find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec scanelf --needed --nobanner --format '%n#p' '{}' ';' \
+		| tr ',' '\n' \
+		| sort -u \
+		| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
+		| xargs -rt apk add --no-cache --virtual .python-rundeps \
+	&& apk del .build-deps \
+	\
+	&& find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \
+			\( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \
+		\) -exec rm -rf '{}' + \
+	&& rm -rf /usr/src/python \
+	\
+	&& python3 --version
+
+# make some useful symlinks that are expected to exist
+RUN cd /usr/local/bin \
+	&& ln -s idle3 idle \
+	&& ln -s pydoc3 pydoc \
+	&& ln -s python3 python \
+	&& ln -s python3-config python-config
+
+# if this is called "PIP_VERSION", pip explodes with "ValueError: invalid truth value '<VERSION>'"
+ENV PYTHON_PIP_VERSION 19.3.1
+# https://github.com/pypa/get-pip
+ENV PYTHON_GET_PIP_URL https://github.com/pypa/get-pip/raw/ffe826207a010164265d9cc807978e3604d18ca0/get-pip.py
+ENV PYTHON_GET_PIP_SHA256 b86f36cc4345ae87bfd4f10ef6b2dbfa7a872fbff70608a1e43944d283fd0eee
+
+RUN set -ex; \
+	\
+	wget -O get-pip.py "$PYTHON_GET_PIP_URL"; \
+	echo "$PYTHON_GET_PIP_SHA256 *get-pip.py" | sha256sum -c -; \
+	\
+	python get-pip.py \
+		--disable-pip-version-check \
+		--no-cache-dir \
+		"pip==$PYTHON_PIP_VERSION" \
+	; \
+	pip --version; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \
+			\( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \
+		\) -exec rm -rf '{}' +; \
+	rm -f get-pip.py
+
+CMD ["python3"]
diff --git a/3.9-rc/buster/Dockerfile b/3.9-rc/buster/Dockerfile
new file mode 100644
index 000000000..8473baaa9
--- /dev/null
+++ b/3.9-rc/buster/Dockerfile
@@ -0,0 +1,95 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "update.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM buildpack-deps:buster
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# http://bugs.python.org/issue19846
+# > At the moment, setting "LANG=C" on a Linux system *fundamentally breaks Python 3*, and that's not OK.
+ENV LANG C.UTF-8
+
+# extra dependencies (over what buildpack-deps already includes)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+		tk-dev \
+		uuid-dev \
+	&& rm -rf /var/lib/apt/lists/*
+
+ENV GPG_KEY E3FF2839C048B25C084DEBE9B26995E310250568
+ENV PYTHON_VERSION 3.9.0a1
+
+RUN set -ex \
+	\
+	&& wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" \
+	&& wget -O python.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" \
+	&& export GNUPGHOME="$(mktemp -d)" \
+	&& gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys "$GPG_KEY" \
+	&& gpg --batch --verify python.tar.xz.asc python.tar.xz \
+	&& { command -v gpgconf > /dev/null && gpgconf --kill all || :; } \
+	&& rm -rf "$GNUPGHOME" python.tar.xz.asc \
+	&& mkdir -p /usr/src/python \
+	&& tar -xJC /usr/src/python --strip-components=1 -f python.tar.xz \
+	&& rm python.tar.xz \
+	\
+	&& cd /usr/src/python \
+	&& gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
+	&& ./configure \
+		--build="$gnuArch" \
+		--enable-loadable-sqlite-extensions \
+		--enable-optimizations \
+		--enable-shared \
+		--with-system-expat \
+		--with-system-ffi \
+		--without-ensurepip \
+	&& make -j "$(nproc)" \
+	&& make install \
+	&& ldconfig \
+	\
+	&& find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \
+			\( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \
+		\) -exec rm -rf '{}' + \
+	&& rm -rf /usr/src/python \
+	\
+	&& python3 --version
+
+# make some useful symlinks that are expected to exist
+RUN cd /usr/local/bin \
+	&& ln -s idle3 idle \
+	&& ln -s pydoc3 pydoc \
+	&& ln -s python3 python \
+	&& ln -s python3-config python-config
+
+# if this is called "PIP_VERSION", pip explodes with "ValueError: invalid truth value '<VERSION>'"
+ENV PYTHON_PIP_VERSION 19.3.1
+# https://github.com/pypa/get-pip
+ENV PYTHON_GET_PIP_URL https://github.com/pypa/get-pip/raw/ffe826207a010164265d9cc807978e3604d18ca0/get-pip.py
+ENV PYTHON_GET_PIP_SHA256 b86f36cc4345ae87bfd4f10ef6b2dbfa7a872fbff70608a1e43944d283fd0eee
+
+RUN set -ex; \
+	\
+	wget -O get-pip.py "$PYTHON_GET_PIP_URL"; \
+	echo "$PYTHON_GET_PIP_SHA256 *get-pip.py" | sha256sum --check --strict -; \
+	\
+	python get-pip.py \
+		--disable-pip-version-check \
+		--no-cache-dir \
+		"pip==$PYTHON_PIP_VERSION" \
+	; \
+	pip --version; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \
+			\( -type f -a \( -name '*.pyc' -o -name '*.pyo' \) \) \
+		\) -exec rm -rf '{}' +; \
+	rm -f get-pip.py
+
+CMD ["python3"]
diff --git a/3.9-rc/windows/windowsservercore-1809/Dockerfile b/3.9-rc/windows/windowsservercore-1809/Dockerfile
new file mode 100644
index 000000000..79533d17e
--- /dev/null
+++ b/3.9-rc/windows/windowsservercore-1809/Dockerfile
@@ -0,0 +1,72 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "update.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM mcr.microsoft.com/windows/servercore:1809
+
+SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+
+ENV PYTHON_VERSION 3.9.0a1
+ENV PYTHON_RELEASE 3.9.0
+
+RUN $url = ('https://www.python.org/ftp/python/{0}/python-{1}-amd64.exe' -f $env:PYTHON_RELEASE, $env:PYTHON_VERSION); \
+	Write-Host ('Downloading {0} ...' -f $url); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $url -OutFile 'python.exe'; \
+	\
+	Write-Host 'Installing ...'; \
+# https://docs.python.org/3.5/using/windows.html#installing-without-ui
+	Start-Process python.exe -Wait \
+		-ArgumentList @( \
+			'/quiet', \
+			'InstallAllUsers=1', \
+			'TargetDir=C:\Python', \
+			'PrependPath=1', \
+			'Shortcuts=0', \
+			'Include_doc=0', \
+			'Include_pip=0', \
+			'Include_test=0' \
+		); \
+	\
+# the installer updated PATH, so we should refresh our local value
+	$env:PATH = [Environment]::GetEnvironmentVariable('PATH', [EnvironmentVariableTarget]::Machine); \
+	\
+	Write-Host 'Verifying install ...'; \
+	Write-Host '  python --version'; python --version; \
+	\
+	Write-Host 'Removing ...'; \
+	Remove-Item python.exe -Force; \
+	\
+	Write-Host 'Complete.'
+
+# if this is called "PIP_VERSION", pip explodes with "ValueError: invalid truth value '<VERSION>'"
+ENV PYTHON_PIP_VERSION 19.3.1
+# https://github.com/pypa/get-pip
+ENV PYTHON_GET_PIP_URL https://github.com/pypa/get-pip/raw/ffe826207a010164265d9cc807978e3604d18ca0/get-pip.py
+ENV PYTHON_GET_PIP_SHA256 b86f36cc4345ae87bfd4f10ef6b2dbfa7a872fbff70608a1e43944d283fd0eee
+
+RUN Write-Host ('Downloading get-pip.py ({0}) ...' -f $env:PYTHON_GET_PIP_URL); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $env:PYTHON_GET_PIP_URL -OutFile 'get-pip.py'; \
+	Write-Host ('Verifying sha256 ({0}) ...' -f $env:PYTHON_GET_PIP_SHA256); \
+	if ((Get-FileHash 'get-pip.py' -Algorithm sha256).Hash -ne $env:PYTHON_GET_PIP_SHA256) { \
+		Write-Host 'FAILED!'; \
+		exit 1; \
+	}; \
+	\
+	Write-Host ('Installing pip=={0} ...' -f $env:PYTHON_PIP_VERSION); \
+	python get-pip.py \
+		--disable-pip-version-check \
+		--no-cache-dir \
+		('pip=={0}' -f $env:PYTHON_PIP_VERSION) \
+	; \
+	Remove-Item get-pip.py -Force; \
+	\
+	Write-Host 'Verifying pip install ...'; \
+	pip --version; \
+	\
+	Write-Host 'Complete.'
+
+CMD ["python"]
diff --git a/3.9-rc/windows/windowsservercore-ltsc2016/Dockerfile b/3.9-rc/windows/windowsservercore-ltsc2016/Dockerfile
new file mode 100644
index 000000000..3b3c4b6ab
--- /dev/null
+++ b/3.9-rc/windows/windowsservercore-ltsc2016/Dockerfile
@@ -0,0 +1,72 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "update.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM mcr.microsoft.com/windows/servercore:ltsc2016
+
+SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+
+ENV PYTHON_VERSION 3.9.0a1
+ENV PYTHON_RELEASE 3.9.0
+
+RUN $url = ('https://www.python.org/ftp/python/{0}/python-{1}-amd64.exe' -f $env:PYTHON_RELEASE, $env:PYTHON_VERSION); \
+	Write-Host ('Downloading {0} ...' -f $url); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $url -OutFile 'python.exe'; \
+	\
+	Write-Host 'Installing ...'; \
+# https://docs.python.org/3.5/using/windows.html#installing-without-ui
+	Start-Process python.exe -Wait \
+		-ArgumentList @( \
+			'/quiet', \
+			'InstallAllUsers=1', \
+			'TargetDir=C:\Python', \
+			'PrependPath=1', \
+			'Shortcuts=0', \
+			'Include_doc=0', \
+			'Include_pip=0', \
+			'Include_test=0' \
+		); \
+	\
+# the installer updated PATH, so we should refresh our local value
+	$env:PATH = [Environment]::GetEnvironmentVariable('PATH', [EnvironmentVariableTarget]::Machine); \
+	\
+	Write-Host 'Verifying install ...'; \
+	Write-Host '  python --version'; python --version; \
+	\
+	Write-Host 'Removing ...'; \
+	Remove-Item python.exe -Force; \
+	\
+	Write-Host 'Complete.'
+
+# if this is called "PIP_VERSION", pip explodes with "ValueError: invalid truth value '<VERSION>'"
+ENV PYTHON_PIP_VERSION 19.3.1
+# https://github.com/pypa/get-pip
+ENV PYTHON_GET_PIP_URL https://github.com/pypa/get-pip/raw/ffe826207a010164265d9cc807978e3604d18ca0/get-pip.py
+ENV PYTHON_GET_PIP_SHA256 b86f36cc4345ae87bfd4f10ef6b2dbfa7a872fbff70608a1e43944d283fd0eee
+
+RUN Write-Host ('Downloading get-pip.py ({0}) ...' -f $env:PYTHON_GET_PIP_URL); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $env:PYTHON_GET_PIP_URL -OutFile 'get-pip.py'; \
+	Write-Host ('Verifying sha256 ({0}) ...' -f $env:PYTHON_GET_PIP_SHA256); \
+	if ((Get-FileHash 'get-pip.py' -Algorithm sha256).Hash -ne $env:PYTHON_GET_PIP_SHA256) { \
+		Write-Host 'FAILED!'; \
+		exit 1; \
+	}; \
+	\
+	Write-Host ('Installing pip=={0} ...' -f $env:PYTHON_PIP_VERSION); \
+	python get-pip.py \
+		--disable-pip-version-check \
+		--no-cache-dir \
+		('pip=={0}' -f $env:PYTHON_PIP_VERSION) \
+	; \
+	Remove-Item get-pip.py -Force; \
+	\
+	Write-Host 'Verifying pip install ...'; \
+	pip --version; \
+	\
+	Write-Host 'Complete.'
+
+CMD ["python"]
diff --git a/update.sh b/update.sh
index d44ab381a..9cf7345ae 100755
--- a/update.sh
+++ b/update.sh
@@ -23,6 +23,10 @@ declare -A gpgKeys=(
 	# gpg: key B26995E310250568: public key "\xc5\x81ukasz Langa (GPG langa.pl) <lukasz@langa.pl>" imported
 	[3.8]='E3FF2839C048B25C084DEBE9B26995E310250568'
 	# https://www.python.org/dev/peps/pep-0569/#release-manager-and-crew
+
+	# gpg: key B26995E310250568: public key "\xc5\x81ukasz Langa (GPG langa.pl) <lukasz@langa.pl>" imported
+	[3.9]='E3FF2839C048B25C084DEBE9B26995E310250568'
+	# https://www.python.org/dev/peps/pep-0596/#release-manager-and-crew
 )
 
 cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"