diff --git a/3.15-rc/alpine3.21/Dockerfile b/3.15-rc/alpine3.21/Dockerfile
new file mode 100644
index 000000000..3348b3b02
--- /dev/null
+++ b/3.15-rc/alpine3.21/Dockerfile
@@ -0,0 +1,138 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM alpine:3.21
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apk add --no-cache \
+		ca-certificates \
+		tzdata \
+	;
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	apk add --no-cache --virtual .build-deps \
+		bluez-dev \
+		bzip2-dev \
+		dpkg-dev dpkg \
+		findutils \
+		gcc \
+		gdbm-dev \
+		gnupg \
+		libc-dev \
+		libffi-dev \
+		libnsl-dev \
+		libtirpc-dev \
+		linux-headers \
+		make \
+		ncurses-dev \
+		openssl-dev \
+		pax-utils \
+		readline-dev \
+		sqlite-dev \
+		tar \
+		tcl-dev \
+		tk \
+		tk-dev \
+		util-linux-dev \
+		xz \
+		xz-dev \
+		zlib-dev \
+		zstd-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file 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-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+# set thread stack size to 1MB so we don't segfault before we hit sys.getrecursionlimit()
+# https://github.com/alpinelinux/aports/commit/2026e1259422d4e0cf92391ca2d3844356c649d0
+	EXTRA_CFLAGS="-DTHREAD_STACK_SIZE=0x100000"; \
+	LDFLAGS="${LDFLAGS:--Wl},--strip-all"; \
+		arch="$(apk --print-arch)"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			x86_64|aarch64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			x86) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	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:" $1 }' \
+		| xargs -rt apk add --no-network --virtual .python-rundeps \
+	; \
+	apk del --no-network .build-deps; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/alpine3.22/Dockerfile b/3.15-rc/alpine3.22/Dockerfile
new file mode 100644
index 000000000..ef2eeb252
--- /dev/null
+++ b/3.15-rc/alpine3.22/Dockerfile
@@ -0,0 +1,138 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM alpine:3.22
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apk add --no-cache \
+		ca-certificates \
+		tzdata \
+	;
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	apk add --no-cache --virtual .build-deps \
+		bluez-dev \
+		bzip2-dev \
+		dpkg-dev dpkg \
+		findutils \
+		gcc \
+		gdbm-dev \
+		gnupg \
+		libc-dev \
+		libffi-dev \
+		libnsl-dev \
+		libtirpc-dev \
+		linux-headers \
+		make \
+		ncurses-dev \
+		openssl-dev \
+		pax-utils \
+		readline-dev \
+		sqlite-dev \
+		tar \
+		tcl-dev \
+		tk \
+		tk-dev \
+		util-linux-dev \
+		xz \
+		xz-dev \
+		zlib-dev \
+		zstd-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file python.tar.xz; \
+	rm python.tar.xz; \
+	\
+	cd /usr/src/python; \
+	gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \
+	./configure \
+		--build="$gnuArch" \
+		--enable-loadable-sqlite-extensions \
+		--enable-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+# set thread stack size to 1MB so we don't segfault before we hit sys.getrecursionlimit()
+# https://github.com/alpinelinux/aports/commit/2026e1259422d4e0cf92391ca2d3844356c649d0
+	EXTRA_CFLAGS="-DTHREAD_STACK_SIZE=0x100000"; \
+	LDFLAGS="${LDFLAGS:--Wl},--strip-all"; \
+		arch="$(apk --print-arch)"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			x86_64|aarch64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			x86) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	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:" $1 }' \
+		| xargs -rt apk add --no-network --virtual .python-rundeps \
+	; \
+	apk del --no-network .build-deps; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/bookworm/Dockerfile b/3.15-rc/bookworm/Dockerfile
new file mode 100644
index 000000000..857dc42b2
--- /dev/null
+++ b/3.15-rc/bookworm/Dockerfile
@@ -0,0 +1,130 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM buildpack-deps:bookworm
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		libbluetooth-dev \
+		tk-dev \
+		uuid-dev \
+	; \
+	rm -rf /var/lib/apt/lists/*
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		libzstd-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file 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-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+	EXTRA_CFLAGS="$(dpkg-buildflags --get CFLAGS)"; \
+	LDFLAGS="$(dpkg-buildflags --get LDFLAGS)"; \
+		arch="$(dpkg --print-architecture)"; arch="${arch##*-}"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			amd64|arm64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			i386) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+# enable GDB to load debugging data: https://github.com/docker-library/python/pull/701
+	bin="$(readlink -ve /usr/local/bin/python3)"; \
+	dir="$(dirname "$bin")"; \
+	mkdir -p "/usr/share/gdb/auto-load/$dir"; \
+	cp -vL Tools/gdb/libpython.py "/usr/share/gdb/auto-load/$bin-gdb.py"; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	ldconfig; \
+	\
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
+		| awk '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); printf "*%s\n", so }' \
+		| sort -u \
+		| xargs -rt dpkg-query --search \
+# https://manpages.debian.org/bookworm/dpkg/dpkg-query.1.en.html#S (we ignore diversions and it'll be really unusual for more than one package to provide any given .so file)
+		| awk 'sub(":$", "", $1) { print $1 }' \
+		| sort -u \
+		| xargs -r apt-mark manual \
+	; \
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/slim-bookworm/Dockerfile b/3.15-rc/slim-bookworm/Dockerfile
new file mode 100644
index 000000000..5f9e76b44
--- /dev/null
+++ b/3.15-rc/slim-bookworm/Dockerfile
@@ -0,0 +1,145 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM debian:bookworm-slim
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		ca-certificates \
+		netbase \
+		tzdata \
+	; \
+	rm -rf /var/lib/apt/lists/*
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		dpkg-dev \
+		gcc \
+		gnupg \
+		libbluetooth-dev \
+		libbz2-dev \
+		libc6-dev \
+		libdb-dev \
+		libffi-dev \
+		libgdbm-dev \
+		liblzma-dev \
+		libncursesw5-dev \
+		libreadline-dev \
+		libsqlite3-dev \
+		libssl-dev \
+		libzstd-dev \
+		make \
+		tk-dev \
+		uuid-dev \
+		wget \
+		xz-utils \
+		zlib1g-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file 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-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+	EXTRA_CFLAGS="$(dpkg-buildflags --get CFLAGS)"; \
+	LDFLAGS="$(dpkg-buildflags --get LDFLAGS)"; \
+	LDFLAGS="${LDFLAGS:--Wl},--strip-all"; \
+		arch="$(dpkg --print-architecture)"; arch="${arch##*-}"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			amd64|arm64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			i386) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	ldconfig; \
+	\
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
+		| awk '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); printf "*%s\n", so }' \
+		| sort -u \
+		| xargs -rt dpkg-query --search \
+# https://manpages.debian.org/bookworm/dpkg/dpkg-query.1.en.html#S (we ignore diversions and it'll be really unusual for more than one package to provide any given .so file)
+		| awk 'sub(":$", "", $1) { print $1 }' \
+		| sort -u \
+		| xargs -r apt-mark manual \
+	; \
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/slim-trixie/Dockerfile b/3.15-rc/slim-trixie/Dockerfile
new file mode 100644
index 000000000..75f9eb810
--- /dev/null
+++ b/3.15-rc/slim-trixie/Dockerfile
@@ -0,0 +1,145 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM debian:trixie-slim
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		ca-certificates \
+		netbase \
+		tzdata \
+	; \
+	apt-get dist-clean
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		dpkg-dev \
+		gcc \
+		gnupg \
+		libbluetooth-dev \
+		libbz2-dev \
+		libc6-dev \
+		libdb-dev \
+		libffi-dev \
+		libgdbm-dev \
+		liblzma-dev \
+		libncursesw5-dev \
+		libreadline-dev \
+		libsqlite3-dev \
+		libssl-dev \
+		libzstd-dev \
+		make \
+		tk-dev \
+		uuid-dev \
+		wget \
+		xz-utils \
+		zlib1g-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file 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-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+	EXTRA_CFLAGS="$(dpkg-buildflags --get CFLAGS)"; \
+	LDFLAGS="$(dpkg-buildflags --get LDFLAGS)"; \
+	LDFLAGS="${LDFLAGS:--Wl},--strip-all"; \
+		arch="$(dpkg --print-architecture)"; arch="${arch##*-}"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			amd64|arm64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			i386) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	ldconfig; \
+	\
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
+		| awk '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); printf "*%s\n", so }' \
+		| sort -u \
+		| xargs -rt dpkg-query --search \
+# https://manpages.debian.org/bookworm/dpkg/dpkg-query.1.en.html#S (we ignore diversions and it'll be really unusual for more than one package to provide any given .so file)
+		| awk 'sub(":$", "", $1) { print $1 }' \
+		| sort -u \
+		| xargs -r apt-mark manual \
+	; \
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	apt-get dist-clean; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/trixie/Dockerfile b/3.15-rc/trixie/Dockerfile
new file mode 100644
index 000000000..f08c12d91
--- /dev/null
+++ b/3.15-rc/trixie/Dockerfile
@@ -0,0 +1,130 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM buildpack-deps:trixie
+
+# ensure local python is preferred over distribution python
+ENV PATH /usr/local/bin:$PATH
+
+# runtime dependencies
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		libbluetooth-dev \
+		tk-dev \
+		uuid-dev \
+	; \
+	apt-get dist-clean
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4
+
+RUN set -eux; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		libzstd-dev \
+	; \
+	\
+	wget -O python.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz"; \
+	echo "$PYTHON_SHA256 *python.tar.xz" | sha256sum -c -; \
+	mkdir -p /usr/src/python; \
+	tar --extract --directory /usr/src/python --strip-components=1 --file 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-option-checking=fatal \
+		--enable-shared \
+		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
+		--with-ensurepip \
+	; \
+	nproc="$(nproc)"; \
+	EXTRA_CFLAGS="$(dpkg-buildflags --get CFLAGS)"; \
+	LDFLAGS="$(dpkg-buildflags --get LDFLAGS)"; \
+		arch="$(dpkg --print-architecture)"; arch="${arch##*-}"; \
+# https://docs.python.org/3.12/howto/perf_profiling.html
+# https://github.com/docker-library/python/pull/1000#issuecomment-2597021615
+		case "$arch" in \
+			amd64|arm64) \
+				# only add "-mno-omit-leaf" on arches that support it
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/x86-Options.html#index-momit-leaf-frame-pointer-2
+				# https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/AArch64-Options.html#index-momit-leaf-frame-pointer
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer"; \
+				;; \
+			i386) \
+				# don't enable frame-pointers on 32bit x86 due to performance drop.
+				;; \
+			*) \
+				# other arches don't support "-mno-omit-leaf"
+				EXTRA_CFLAGS="${EXTRA_CFLAGS:-} -fno-omit-frame-pointer"; \
+				;; \
+		esac; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:-}" \
+	; \
+# https://github.com/docker-library/python/issues/784
+# prevent accidental usage of a system installed libpython of the same version
+	rm python; \
+	make -j "$nproc" \
+		"EXTRA_CFLAGS=${EXTRA_CFLAGS:-}" \
+		"LDFLAGS=${LDFLAGS:--Wl},-rpath='\$\$ORIGIN/../lib'" \
+		python \
+	; \
+	make install; \
+	\
+# enable GDB to load debugging data: https://github.com/docker-library/python/pull/701
+	bin="$(readlink -ve /usr/local/bin/python3)"; \
+	dir="$(dirname "$bin")"; \
+	mkdir -p "/usr/share/gdb/auto-load/$dir"; \
+	cp -vL Tools/gdb/libpython.py "/usr/share/gdb/auto-load/$bin-gdb.py"; \
+	\
+	cd /; \
+	rm -rf /usr/src/python; \
+	\
+	find /usr/local -depth \
+		\( \
+			\( -type d -a \( -name test -o -name tests -o -name idle_test \) \) \
+			-o \( -type f -a \( -name '*.pyc' -o -name '*.pyo' -o -name 'libpython*.a' \) \) \
+		\) -exec rm -rf '{}' + \
+	; \
+	\
+	ldconfig; \
+	\
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	find /usr/local -type f -executable -not \( -name '*tkinter*' \) -exec ldd '{}' ';' \
+		| awk '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); printf "*%s\n", so }' \
+		| sort -u \
+		| xargs -rt dpkg-query --search \
+# https://manpages.debian.org/bookworm/dpkg/dpkg-query.1.en.html#S (we ignore diversions and it'll be really unusual for more than one package to provide any given .so file)
+		| awk 'sub(":$", "", $1) { print $1 }' \
+		| sort -u \
+		| xargs -r apt-mark manual \
+	; \
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	apt-get dist-clean; \
+	\
+	export PYTHONDONTWRITEBYTECODE=1; \
+	python3 --version; \
+	pip3 --version
+
+# make some useful symlinks that are expected to exist ("/usr/local/bin/python" and friends)
+RUN set -eux; \
+	for src in idle3 pip3 pydoc3 python3 python3-config; do \
+		dst="$(echo "$src" | tr -d 3)"; \
+		[ -s "/usr/local/bin/$src" ]; \
+		[ ! -e "/usr/local/bin/$dst" ]; \
+		ln -svT "$src" "/usr/local/bin/$dst"; \
+	done
+
+CMD ["python3"]
diff --git a/3.15-rc/windows/windowsservercore-ltsc2022/Dockerfile b/3.15-rc/windows/windowsservercore-ltsc2022/Dockerfile
new file mode 100644
index 000000000..da05a9c20
--- /dev/null
+++ b/3.15-rc/windows/windowsservercore-ltsc2022/Dockerfile
@@ -0,0 +1,65 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM mcr.microsoft.com/windows/servercore:ltsc2022
+
+SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+
+# https://github.com/docker-library/python/pull/557
+ENV PYTHONIOENCODING UTF-8
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 376a4b54b3b6fd5b0614b5c0d5a5a3d75b89861102e2f3d6166b2bf5c6d925bb
+
+RUN $url = ('https://www.python.org/ftp/python/{0}/python-{1}-amd64.exe' -f ($env:PYTHON_VERSION -replace '[a-z]+[0-9]*$', ''), $env:PYTHON_VERSION); \
+	Write-Host ('Downloading {0} ...' -f $url); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $url -OutFile 'python.exe'; \
+	\
+	Write-Host ('Verifying sha256 ({0}) ...' -f $env:PYTHON_SHA256); \
+	if ((Get-FileHash python.exe -Algorithm sha256).Hash -ne $env:PYTHON_SHA256) { \
+		Write-Host 'FAILED!'; \
+		exit 1; \
+	}; \
+	\
+	Write-Host 'Installing ...'; \
+# https://docs.python.org/3/using/windows.html#installing-without-ui
+	$exitCode = (Start-Process python.exe -Wait -NoNewWindow -PassThru \
+		-ArgumentList @( \
+			'/quiet', \
+			'InstallAllUsers=1', \
+			'TargetDir=C:\Python', \
+			'PrependPath=1', \
+			'Shortcuts=0', \
+			'Include_doc=0', \
+			'Include_pip=1', \
+			'Include_test=0' \
+		) \
+	).ExitCode; \
+	if ($exitCode -ne 0) { \
+		Write-Host ('Running python installer failed with exit code: {0}' -f $exitCode); \
+		Get-ChildItem $env:TEMP | Sort-Object -Descending -Property LastWriteTime | Select-Object -First 1 | Get-Content; \
+		exit $exitCode; \
+	} \
+	\
+# 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; \
+	Remove-Item $env:TEMP/Python*.log -Force; \
+	\
+	$env:PYTHONDONTWRITEBYTECODE = '1'; \
+	\
+	Write-Host 'Verifying pip install ...'; \
+	pip --version; \
+	\
+	Write-Host 'Complete.'
+
+CMD ["python"]
diff --git a/3.15-rc/windows/windowsservercore-ltsc2025/Dockerfile b/3.15-rc/windows/windowsservercore-ltsc2025/Dockerfile
new file mode 100644
index 000000000..9424923b3
--- /dev/null
+++ b/3.15-rc/windows/windowsservercore-ltsc2025/Dockerfile
@@ -0,0 +1,65 @@
+#
+# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+#
+# PLEASE DO NOT EDIT IT DIRECTLY.
+#
+
+FROM mcr.microsoft.com/windows/servercore:ltsc2025
+
+SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+
+# https://github.com/docker-library/python/pull/557
+ENV PYTHONIOENCODING UTF-8
+
+ENV PYTHON_VERSION 3.15.0a1
+ENV PYTHON_SHA256 376a4b54b3b6fd5b0614b5c0d5a5a3d75b89861102e2f3d6166b2bf5c6d925bb
+
+RUN $url = ('https://www.python.org/ftp/python/{0}/python-{1}-amd64.exe' -f ($env:PYTHON_VERSION -replace '[a-z]+[0-9]*$', ''), $env:PYTHON_VERSION); \
+	Write-Host ('Downloading {0} ...' -f $url); \
+	[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; \
+	Invoke-WebRequest -Uri $url -OutFile 'python.exe'; \
+	\
+	Write-Host ('Verifying sha256 ({0}) ...' -f $env:PYTHON_SHA256); \
+	if ((Get-FileHash python.exe -Algorithm sha256).Hash -ne $env:PYTHON_SHA256) { \
+		Write-Host 'FAILED!'; \
+		exit 1; \
+	}; \
+	\
+	Write-Host 'Installing ...'; \
+# https://docs.python.org/3/using/windows.html#installing-without-ui
+	$exitCode = (Start-Process python.exe -Wait -NoNewWindow -PassThru \
+		-ArgumentList @( \
+			'/quiet', \
+			'InstallAllUsers=1', \
+			'TargetDir=C:\Python', \
+			'PrependPath=1', \
+			'Shortcuts=0', \
+			'Include_doc=0', \
+			'Include_pip=1', \
+			'Include_test=0' \
+		) \
+	).ExitCode; \
+	if ($exitCode -ne 0) { \
+		Write-Host ('Running python installer failed with exit code: {0}' -f $exitCode); \
+		Get-ChildItem $env:TEMP | Sort-Object -Descending -Property LastWriteTime | Select-Object -First 1 | Get-Content; \
+		exit $exitCode; \
+	} \
+	\
+# 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; \
+	Remove-Item $env:TEMP/Python*.log -Force; \
+	\
+	$env:PYTHONDONTWRITEBYTECODE = '1'; \
+	\
+	Write-Host 'Verifying pip install ...'; \
+	pip --version; \
+	\
+	Write-Host 'Complete.'
+
+CMD ["python"]
diff --git a/versions.json b/versions.json
index 2fce14a35..271adca08 100644
--- a/versions.json
+++ b/versions.json
@@ -95,6 +95,27 @@
     ],
     "version": "3.14.0"
   },
+  "3.15-rc": {
+    "checksums": {
+      "source": {
+        "sha256": "3194939d488eeaeefdcf990d35542d9ad1ce788789c4e2305a2060eb7058e5a4"
+      },
+      "windows": {
+        "sha256": "376a4b54b3b6fd5b0614b5c0d5a5a3d75b89861102e2f3d6166b2bf5c6d925bb"
+      }
+    },
+    "variants": [
+      "trixie",
+      "slim-trixie",
+      "bookworm",
+      "slim-bookworm",
+      "alpine3.22",
+      "alpine3.21",
+      "windows/windowsservercore-ltsc2025",
+      "windows/windowsservercore-ltsc2022"
+    ],
+    "version": "3.15.0a1"
+  },
   "3.9": {
     "checksums": {
       "source": {