diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3f96812..6d8f578 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -54,6 +54,14 @@ jobs:
             build: unit
             build_type: Debug
 
+          - name: "Unit clang19 (libc++) c++23"
+            cxx: "clang++-19"
+            cc: "clang-19"
+            pkg: "clang-19 libc++-19-dev libc++abi-19-dev libc++1-19 libc++abi1-19"
+            cxx_flags: "-std=c++23 -stdlib=libc++"
+            build: unit
+            build_type: Debug
+
           - name: "Unit gcc11 Release"
             cxx: "g++-11"
             cc: "gcc-11"
@@ -127,6 +135,7 @@ jobs:
         run: |
           sudo apt-add-repository --no-update --yes "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main"
           sudo apt-add-repository --no-update --yes "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-18 main"
+          sudo apt-add-repository --no-update --yes "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-19 main"
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
 
       - name: Configure APT
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 105c3b9..93b5af4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## unreleased
+## [0.20.0] - 2025-08-03
+
+First release. "Full C++20 equivalence."
 
 ### Progress implementing std::views::X equivalents
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..6f7407e
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required (VERSION 3.12)
+
+project (radr LANGUAGES CXX
+         DESCRIPTION "Range Adaptors Reimagined (radr)."
+         HOMEPAGE_URL "https://github.com/h-2/radr")
+
+message(STATUS "Loading the RADR library and implicitly calling find_package.")
+find_package (radr REQUIRED HINTS ${CMAKE_CURRENT_LIST_DIR}/cmake)
+message(STATUS "Add radr::radr to your program's target_link_libraries.")
+
+message(STATUS "ATTENTION: Including the project root only includes the library.")
+message(STATUS "ATTENTION: To build unit tests, benchmarks or other utilitites, directly cmake one of the directories in tests/ .")
diff --git a/cmake/radr-config.cmake b/cmake/radr-config.cmake
new file mode 100644
index 0000000..e1ed5f7
--- /dev/null
+++ b/cmake/radr-config.cmake
@@ -0,0 +1,8 @@
+cmake_minimum_required (VERSION 3.12)
+
+find_path (RADR_CLONE_DIR NAMES cmake/radr-config.cmake HINTS "${CMAKE_CURRENT_LIST_DIR}/..")
+find_path (RADR_INCLUDE_DIR NAMES radr/version.hpp HINTS "${RADR_CLONE_DIR}/include")
+
+add_library (radr_radr INTERFACE)
+target_include_directories (radr_radr INTERFACE "${RADR_INCLUDE_DIR}")
+add_library (radr::radr ALIAS radr_radr)
diff --git a/include/radr/custom/tags.hpp b/include/radr/custom/tags.hpp
index eed3829..94cd483 100644
--- a/include/radr/custom/tags.hpp
+++ b/include/radr/custom/tags.hpp
@@ -11,6 +11,8 @@
 
 #pragma once
 
+#include "radr/version.hpp"
+
 namespace radr::custom
 {
 
diff --git a/include/radr/detail/detail.hpp b/include/radr/detail/detail.hpp
index f1eb560..c9bb5bd 100644
--- a/include/radr/detail/detail.hpp
+++ b/include/radr/detail/detail.hpp
@@ -16,6 +16,7 @@
 #include <iterator>
 #include <ranges>
 
+#include "../version.hpp"
 #include "bind_back.hpp"
 #include "fwd.hpp"
 
diff --git a/include/radr/version.hpp b/include/radr/version.hpp
new file mode 100644
index 0000000..460f046
--- /dev/null
+++ b/include/radr/version.hpp
@@ -0,0 +1,47 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Copyright (c) 2023-2025 Hannes Hauswedell
+//
+// Licensed under the Apache License v2.0 with LLVM Exceptions.
+// See the LICENSE file for details.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include <cinttypes>
+#include <ciso646> // makes _LIBCPP_VERSION available
+#include <cstddef> // makes __GLIBCXX__ available
+
+// ============================================================================
+//  C++ standard and features
+// ============================================================================
+
+// C++ standard [required]
+#ifdef __cplusplus
+static_assert(__cplusplus >= 201709, "RADR requires C++20 or later, make sure that you have set -std=c++20.");
+#else
+#    error "This is not a C++ compiler."
+#endif
+
+#if __has_include(<version>)
+#    include <version>
+#endif
+
+// ============================================================================
+//  Compilers
+// ============================================================================
+
+#if !(defined(__clang_major__) && (__clang_major__ >= 16)) && !(defined(__GNUC__) && (__GNUC__ >= 11))
+#    pragma GCC warning "Only Clang >= 16 and GCC >= 11 are officially supported."
+#endif
+
+// ============================================================================
+//  Version
+// ============================================================================
+
+#define RADR_VERSION_MAJOR 0
+#define RADR_VERSION_MINOR 20
+#define RADR_VERSION_PATCH 0
diff --git a/tests/benchmark/CMakeLists.txt b/tests/benchmark/CMakeLists.txt
index c2d375c..1dc382b 100644
--- a/tests/benchmark/CMakeLists.txt
+++ b/tests/benchmark/CMakeLists.txt
@@ -1,5 +1,5 @@
-cmake_minimum_required (VERSION 3.7)
-project (radr_benchmark CXX)
+cmake_minimum_required (VERSION 3.12)
+project (radr_test_benchmark CXX)
 
 include(FetchContent)
 
@@ -8,14 +8,12 @@ include(FetchContent)
 # ----------------------------------------------------------------------------
 
 message(STATUS "Beginning to configure RADR micro benchmarks...")
+include (../radr-test.cmake)
 
 if (CMAKE_BUILD_TYPE AND NOT ("${CMAKE_BUILD_TYPE}" STREQUAL "Release"))
     message (WARNING "Benchmarks should typically be built in Release mode! [build type = ${CMAKE_BUILD_TYPE}]")
 endif ()
 
-set(CMAKE_CXX_STANDARD 20)
-set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
-
 # ----------------------------------------------------------------------------
 # Options
 # ----------------------------------------------------------------------------
@@ -26,12 +24,7 @@ option(RADR_BENCHMARK_ALIGN_LOOPS "Pass -falign-loops=32 to the benchmark builds
 # Paths to folders.
 # ----------------------------------------------------------------------------
 
-find_path (RADR_BASE_DIR
-           NAMES include/radr/rad/as_const.hpp
-           HINTS "${CMAKE_CURRENT_LIST_DIR}/../../")
-set (RADR_INCLUDE_DIR "${RADR_BASE_DIR}/include/")
-set (RADR_TEST_INCLUDE_DIR "${RADR_BASE_DIR}/tests/include/")
-set (RADR_UNIT_TESTS_SRC "${RADR_BASE_DIR}/tests/benchmark/")
+set (RADR_BENCHMARKS_DIR "${RADR_CLONE_DIR}/tests/benchmark/")
 
 # ----------------------------------------------------------------------------
 # Components and dependencies
@@ -54,47 +47,26 @@ FetchContent_MakeAvailable(googlebenchmark)
 # ----------------------------------------------------------------------------
 
 add_library (radr_benchmark INTERFACE)
-target_compile_options (radr_benchmark INTERFACE "-pedantic"  "-Wall" "-Wextra" "-Werror")
 target_link_libraries (radr_benchmark INTERFACE "pthread" benchmark::benchmark_main)
-target_include_directories (radr_benchmark INTERFACE "${RADR_INCLUDE_DIR}" "${RADR_TEST_INCLUDE_DIR}")
 add_library (radr::test::benchmark ALIAS radr_benchmark)
 
 if (RADR_BENCHMARK_ALIGN_LOOPS)
     target_compile_options (radr_benchmark INTERFACE "-falign-loops=32")
 endif ()
 
-# ----------------------------------------------------------------------------
-# Test target macro
-# ----------------------------------------------------------------------------
-
-macro (radr_test unit_test_cpp)
-    get_filename_component (target_dir "${unit_test_cpp}" DIRECTORY)
-    get_filename_component (target "${unit_test_cpp}" NAME_WLE)
-
-    add_executable (${target} "${RADR_UNIT_TESTS_SRC}/${unit_test_cpp}")
-    target_link_libraries (${target} radr::test::benchmark)
-
-    file (MAKE_DIRECTORY ${target_dir})
-    set_target_properties(${target} PROPERTIES
-                          RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${target_dir}")
-
-    add_test (NAME "${target_dir}/${target}" COMMAND "${target_dir}/${target}")
-
-    unset (target)
-    unset (target_dir)
-endmacro ()
-
 # ----------------------------------------------------------------------------
 # Start generating tests
 # ----------------------------------------------------------------------------
 
 file (GLOB_RECURSE ENTRIES
-      RELATIVE ${RADR_BASE_DIR}/tests/benchmark
-      "${RADR_UNIT_TESTS_SRC}/[!.]*cpp")
+      RELATIVE ${RADR_BENCHMARKS_DIR}
+      "${RADR_BENCHMARKS_DIR}/[!.]*cpp")
 
 foreach (ENTRY ${ENTRIES})
-    message(STATUS ${ENTRY})
-    radr_test(${ENTRY})
+    radr_add_test(${ENTRY})
+    get_filename_component (target "${ENTRY}" NAME_WLE)
+    message(STATUS "Adding benchmark target '${target}' for file ${ENTRY}")
+    target_link_libraries (${target} radr::test::benchmark)
 endforeach ()
 
 message(STATUS "Configuring RADR micro benchmarks DONE.")
diff --git a/tests/include/radr/test/gtest_helpers.hpp b/tests/include/radr/test/gtest_helpers.hpp
index 99cf314..63d1f19 100644
--- a/tests/include/radr/test/gtest_helpers.hpp
+++ b/tests/include/radr/test/gtest_helpers.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <algorithm>
 #include <functional>
 #include <memory>
 #include <ranges>
diff --git a/tests/radr-test.cmake b/tests/radr-test.cmake
index 69f462c..0d3af7e 100644
--- a/tests/radr-test.cmake
+++ b/tests/radr-test.cmake
@@ -1,7 +1,7 @@
 # -*- CMake -*-
 #===----------------------------------------------------------------------===//
 #
-# Copyright (c) 2023 Hannes Hauswedell
+# Copyright (c) 2023-2025 Hannes Hauswedell
 #
 # Licensed under the Apache License v2.0 with LLVM Exceptions.
 # See the LICENSE file for details.
@@ -9,14 +9,15 @@
 #
 #===----------------------------------------------------------------------===//
 
-cmake_minimum_required (VERSION 3.10)
+cmake_minimum_required (VERSION 3.12)
 
 # ----------------------------------------------------------------------------
 # RADR SETUP
 # ----------------------------------------------------------------------------
 
-find_path (RADR_INCLUDE_DIR NAMES radr/rad/as_const.hpp HINTS "${CMAKE_CURRENT_SOURCE_DIR}/../../include/" REQUIRED)
-find_path (RADR_TEST_INCLUDE_DIR NAMES radr/test/gtest_helpers.hpp HINTS "${CMAKE_CURRENT_SOURCE_DIR}/../include/" REQUIRED)
+find_package(radr REQUIRED HINTS "${CMAKE_CURRENT_SOURCE_DIR}/../../cmake/")
+
+find_path (RADR_TEST_INCLUDE_DIR NAMES radr/test/gtest_helpers.hpp HINTS "${RADR_CLONE_DIR}/tests/include/" REQUIRED)
 
 # ----------------------------------------------------------------------------
 # GoogleTest
@@ -35,31 +36,29 @@ FetchContent_MakeAvailable(googletest)
 # Pseudo library to ease target definition
 # ----------------------------------------------------------------------------
 
-add_library (radr_test_unit INTERFACE)
-target_link_libraries (radr_test_unit INTERFACE  gtest_main gtest pthread)
-target_include_directories (radr_test_unit INTERFACE "${RADR_INCLUDE_DIR}" "${RADR_TEST_INCLUDE_DIR}")
-target_compile_options (radr_test_unit INTERFACE -pedantic  -Wall -Wextra -Werror)
-add_library (radr::test::unit ALIAS radr_test_unit)
+add_library (radr_test_base INTERFACE)
+target_link_libraries (radr_test_base INTERFACE  radr::radr gtest_main gtest pthread)
+target_include_directories (radr_test_base INTERFACE "${RADR_TEST_INCLUDE_DIR}")
+target_compile_options (radr_test_base INTERFACE -pedantic  -Wall -Wextra -Werror)
+add_library (radr::test::base ALIAS radr_test_base)
 
 # ----------------------------------------------------------------------------
-# add_subdirectories
+# radr_add_test macro
 # ----------------------------------------------------------------------------
 
-macro (add_subdirectories_of directory)
-    file (GLOB ENTRIES
-          RELATIVE ${directory}
-          ${directory}/[!.]*)
+macro (radr_add_test unit_test_cpp)
+    get_filename_component (target_dir "${unit_test_cpp}" DIRECTORY)
+    get_filename_component (target "${unit_test_cpp}" NAME_WLE)
 
-    foreach (ENTRY ${ENTRIES})
-        if (IS_DIRECTORY ${directory}/${ENTRY})
-            if (EXISTS ${directory}/${ENTRY}/CMakeLists.txt)
-                add_subdirectory (${directory}/${ENTRY} ${CMAKE_CURRENT_BINARY_DIR}/${ENTRY})
-            endif ()
-        endif ()
-    endforeach ()
-    unset (ENTRIES)
-endmacro ()
+    add_executable (${target} "${unit_test_cpp}")
+    target_link_libraries (${target} radr::test::base)
+
+    file (MAKE_DIRECTORY ${target_dir})
+    set_target_properties(${target} PROPERTIES
+                          RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${target_dir}")
+
+    add_test (NAME "${target_dir}/${target}" COMMAND "${target_dir}/${target}")
 
-macro (add_subdirectories)
-    add_subdirectories_of(${CMAKE_CURRENT_SOURCE_DIR})
+    unset (target)
+    unset (target_dir)
 endmacro ()
diff --git a/tests/unit/CMakeLists.txt b/tests/unit/CMakeLists.txt
index 886875b..2130fbd 100644
--- a/tests/unit/CMakeLists.txt
+++ b/tests/unit/CMakeLists.txt
@@ -1,27 +1,22 @@
-cmake_minimum_required (VERSION 3.10)
+cmake_minimum_required (VERSION 3.12)
 project (radr_test_unit CXX)
 
-include (../radr-test.cmake)
+message(STATUS "Beginning to configure RADR unit tests...")
 
-option (RADR_VERBOSE_TESTS "Run each test case individually" OFF)
+include (../radr-test.cmake)
 
-function (radr_unit_test test_name)
-    file (RELATIVE_PATH file_name "${CMAKE_SOURCE_DIR}" "${CMAKE_CURRENT_LIST_DIR}/${test_name}.cpp")
-    set(target_name ${test_name})
+enable_testing()
 
-    add_executable (${target_name} ${test_name}.cpp)
-    target_link_libraries (${target_name} radr::test::unit)
-    if (RADR_VERBOSE_TESTS)
-        gtest_discover_tests(${file_name} TEST_PREFIX "${target_name}::" PROPERTIES TIMEOUT "30")
-    else ()
-        add_test (NAME "${file_name}" COMMAND ${target_name})
-    endif ()
+set (RADR_UNIT_TESTS_SRC "${RADR_CLONE_DIR}/tests/unit/")
 
-    unset (unit_test)
-    unset (target_name)
-    unset (file_name)
-endfunction ()
+file (GLOB_RECURSE ENTRIES
+      RELATIVE ${RADR_UNIT_TESTS_SRC}
+      "${RADR_UNIT_TESTS_SRC}/[!.]*cpp")
 
-enable_testing()
+foreach (ENTRY ${ENTRIES})
+    radr_add_test(${ENTRY})
+    get_filename_component (target "${ENTRY}" NAME_WLE)
+    message(STATUS "Adding unit-test target '${target}' for file ${ENTRY}")
+endforeach ()
 
-add_subdirectories ()
+message(STATUS "Configuring RADR unit tests done.")