diff --git a/index.html b/index.html
index 4f9220d..2bd2559 100644
--- a/index.html
+++ b/index.html
@@ -71,8 +71,9 @@ <h2 id="-≡-contents"><a id="contents"></a> <a href="#contents">≡</a> <a href
 <li><a href="#cppsm-setup"><code>cppsm setup</code></a><ul>
 <li><a href="#cmake_build_type"><code>CMAKE_BUILD_TYPE=Debug|Release</code></a></li>
 <li><a href="#cmake_generator"><code>CMAKE_GENERATOR=&#39;&#39;|&#39;...&#39;</code></a></li>
-<li><a href="#cc"><code>CC=cc|gcc|clang|...</code></a></li>
-<li><a href="#cxx"><code>CXX=c++|g++|clang++|...</code></a></li>
+<li><a href="#cmake_toolchain_file"><code>CMAKE_TOOLCHAIN_FILE=&#39;&#39;|&#39;...&#39;</code></a></li>
+<li><a href="#cc"><code>CC=cc|gcc|clang|emcc|...</code></a></li>
+<li><a href="#cxx"><code>CXX=c++|g++|clang++|emcc|...</code></a></li>
 <li><a href="#clean"><code>CLEAN=0|1</code></a></li>
 <li><a href="#coverage"><code>COVERAGE=0|1</code></a></li>
 </ul>
@@ -101,10 +102,15 @@ <h2 id="-≡-contents"><a id="contents"></a> <a href="#contents">≡</a> <a href
 </ul>
 </li>
 <li><a href="#travis-ci">Travis CI</a><ul>
+<li><a href="#clang"><code>CLANG=1|0</code></a></li>
 <li><a href="#codecov"><code>CODECOV=0|1</code></a></li>
+<li><a href="#emscripten"><code>EMSCRIPTEN=0|1</code></a></li>
 <li><a href="#format_check"><code>FORMAT_CHECK=1|0</code></a></li>
+<li><a href="#gcc"><code>GCC=1|0</code></a></li>
 <li><a href="#install_wait"><code>INSTALL_WAIT=0|1</code></a></li>
 <li><a href="#upgrade_check"><code>UPGRADE_CHECK=1|0</code></a></li>
+<li><a href="#vs2017"><code>VS2017=1|0</code></a></li>
+<li><a href="#vs2019"><code>VS2019=1|0</code></a></li>
 </ul>
 </li>
 <li><a href="#variables">Variables</a><ul>
@@ -340,10 +346,13 @@ <h4 id="-≡-cppsm-setup"><a id="cppsm-setup"></a> <a href="#contents">≡</a> <
 <li><p><a id="cmake_generator"></a><a href="#cmake_generator"><code>CMAKE_GENERATOR=&#39;&#39;|&#39;...&#39;</code></a>
 <a target="_blank" href="https://cmake.org/cmake/help/latest/envvar/CMAKE_GENERATOR.html#envvar:CMAKE_GENERATOR">specifies which generator to use <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
 </li>
-<li><p><a id="cc"></a><a href="#cc"><code>CC=cc|gcc|clang|...</code></a>
+<li><p><a id="cmake_toolchain_file"></a><a href="#cmake_toolchain_file"><code>CMAKE_TOOLCHAIN_FILE=&#39;&#39;|&#39;...&#39;</code></a>
+<a target="_blank" href="https://cmake.org/cmake/help/latest/variable/CMAKE_TOOLCHAIN_FILE.html">specifies toolchain file to use <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
+</li>
+<li><p><a id="cc"></a><a href="#cc"><code>CC=cc|gcc|clang|emcc|...</code></a>
 <a target="_blank" href="https://cmake.org/cmake/help/latest/envvar/CC.html">specifies which C compiler to use <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
 </li>
-<li><p><a id="cxx"></a><a href="#cxx"><code>CXX=c++|g++|clang++|...</code></a>
+<li><p><a id="cxx"></a><a href="#cxx"><code>CXX=c++|g++|clang++|emcc|...</code></a>
 <a target="_blank" href="https://cmake.org/cmake/help/latest/envvar/CXX.html">specifies which C++ compiler to use <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
 </li>
 <li><p><a id="clean"></a><a href="#clean"><code>CLEAN=0|1</code></a> specifies whether the build directory
@@ -456,17 +465,19 @@ <h2 id="-≡-travis-ci"><a id="travis-ci"></a> <a href="#contents">≡</a> <a hr
 provided to build and test both <code>Debug</code> and <code>Release</code> builds on various OS
 (Linux, OS X, Windows) and compiler configurations
 (<a target="_blank" href="https://clang.llvm.org/">Clang <i class="fas fa-xs fa-external-link-alt"></i></a>, <a target="_blank" href="https://gcc.gnu.org/">GCC <i class="fas fa-xs fa-external-link-alt"></i></a>,
-<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a>). Just add your project to
-Travis CI.</p>
+<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a>,
+<a target="_blank" href="https://emscripten.org/">Emscripten <i class="fas fa-xs fa-external-link-alt"></i></a>). Just add your project to Travis CI.</p>
 <ul>
 <li>Linux<ul>
 <li><a target="_blank" href="https://clang.llvm.org/">Clang <i class="fas fa-xs fa-external-link-alt"></i></a> (7)</li>
 <li><a target="_blank" href="https://gcc.gnu.org/">GCC <i class="fas fa-xs fa-external-link-alt"></i></a> (9)</li>
+<li><a target="_blank" href="https://emscripten.org/">Emscripten <i class="fas fa-xs fa-external-link-alt"></i></a> (2)</li>
 </ul>
 </li>
 <li>OS X<ul>
 <li>Apple <a target="_blank" href="https://clang.llvm.org/">Clang <i class="fas fa-xs fa-external-link-alt"></i></a> (12)</li>
 <li><a target="_blank" href="https://gcc.gnu.org/">GCC <i class="fas fa-xs fa-external-link-alt"></i></a> (10)</li>
+<li><a target="_blank" href="https://emscripten.org/">Emscripten <i class="fas fa-xs fa-external-link-alt"></i></a> (2)</li>
 </ul>
 </li>
 <li>Windows<ul>
@@ -477,16 +488,28 @@ <h2 id="-≡-travis-ci"><a id="travis-ci"></a> <a href="#contents">≡</a> <a hr
 </ul>
 <p>Configuration variables:</p>
 <ul>
+<li><p><a id="clang"></a><a href="#clang"><code>CLANG=1|0</code></a> specifies whether to build with
+<a target="_blank" href="https://clang.llvm.org/">Clang <i class="fas fa-xs fa-external-link-alt"></i></a>. Set <code>CLANG=0</code> explicitly to skip building
+with <a target="_blank" href="https://clang.llvm.org/">Clang <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
+</li>
 <li><p><a id="codecov"></a><a href="#codecov"><code>CODECOV=0|1</code></a> specifies whether a code
 coverage test is executed and results are pushed to
 <a target="_blank" href="https://codecov.io/">Codecov <i class="fas fa-xs fa-external-link-alt"></i></a>. Set <code>CODECOV=1</code> explicitly to enable code
 coverage.</p>
 </li>
+<li><p><a id="emscripten"></a><a href="#emscripten"><code>EMSCRIPTEN=0|1</code></a> specifies whether to
+also build with <a target="_blank" href="https://emscripten.org/">Emscripten <i class="fas fa-xs fa-external-link-alt"></i></a>. Set <code>EMSCRIPTEN=1</code>
+explicitly to build with <a target="_blank" href="https://emscripten.org/">Emscripten <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
+</li>
 <li><p><a id="format_check"></a><a href="#format_check"><code>FORMAT_CHECK=1|0</code></a> specifies whether
 to check that source files are formatted as with
 <a href="#cppsm-format"><code>cppsm format</code></a>. Set <code>FORMAT_CHECK=0</code> explicitly to disable
 the format check.</p>
 </li>
+<li><p><a id="gcc"></a><a href="#gcc"><code>GCC=1|0</code></a> specifies whether to build with
+<a target="_blank" href="https://gcc.gnu.org/">GCC <i class="fas fa-xs fa-external-link-alt"></i></a>. Set <code>GCC=0</code> explicitly to skip building with
+<a target="_blank" href="https://gcc.gnu.org/">GCC <i class="fas fa-xs fa-external-link-alt"></i></a>.</p>
+</li>
 <li><p><a id="install_wait"></a><a href="#install_wait"><code>INSTALL_WAIT=0|1</code></a> specifies whether
 installation of additional packages is performed concurrently with builds when
 possible. Set <code>INSTALL_WAIT=1</code> explicitly to wait for installations to
@@ -497,6 +520,16 @@ <h2 id="-≡-travis-ci"><a id="travis-ci"></a> <a href="#contents">≡</a> <a hr
 and, if something is upgraded, tests are rerun. Set <code>UPGRADE_CHECK=0</code>
 explicitly to skip the upgrade and conditional rerun of tests.</p>
 </li>
+<li><p><a id="vs2017"></a><a href="#vs2017"><code>VS2017=1|0</code></a> specifies whether to build with
+<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a> 2017. Set <code>VS2017=0</code>
+explicitly to skip building with
+<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a> 2017.</p>
+</li>
+<li><p><a id="vs2019"></a><a href="#vs2019"><code>VS2019=1|0</code></a> specifies whether to build with
+<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a> 2019. Set <code>VS2019=0</code>
+explicitly to skip building with
+<a target="_blank" href="https://docs.microsoft.com/en-us/cpp/">Visual C++ <i class="fas fa-xs fa-external-link-alt"></i></a> 2019.</p>
+</li>
 </ul>
 <h2 id="-≡-variables"><a id="variables"></a> <a href="#contents">≡</a> <a href="#variables">Variables</a></h2>
 <p>Several environment variables can be set to change the default behavior of one
diff --git a/index.md b/index.md
index 1e9ef2f..80c1694 100644
--- a/index.md
+++ b/index.md
@@ -57,8 +57,9 @@ See [repositories with the `#cppsm` topic](https://github.com/topics/cppsm).
     - [`cppsm setup`](#cppsm-setup)
       - [`CMAKE_BUILD_TYPE=Debug|Release`](#cmake_build_type)
       - [`CMAKE_GENERATOR=''|'...'`](#cmake_generator)
-      - [`CC=cc|gcc|clang|...`](#cc)
-      - [`CXX=c++|g++|clang++|...`](#cxx)
+      - [`CMAKE_TOOLCHAIN_FILE=''|'...'`](#cmake_toolchain_file)
+      - [`CC=cc|gcc|clang|emcc|...`](#cc)
+      - [`CXX=c++|g++|clang++|emcc|...`](#cxx)
       - [`CLEAN=0|1`](#clean)
       - [`COVERAGE=0|1`](#coverage)
     - [`cppsm test`](#cppsm-test)
@@ -75,10 +76,15 @@ See [repositories with the `#cppsm` topic](https://github.com/topics/cppsm).
     - [`add_conventional_executable_tests(...)`](#add_conventional_executable_tests)
     - [`add_conventional_library(${LIBRARY_NAME}_${LIBRARY_VERSION})`](#add_conventional_library)
 - [Travis CI](#travis-ci)
+  - [`CLANG=1|0`](#clang)
   - [`CODECOV=0|1`](#codecov)
+  - [`EMSCRIPTEN=0|1`](#emscripten)
   - [`FORMAT_CHECK=1|0`](#format_check)
+  - [`GCC=1|0`](#gcc)
   - [`INSTALL_WAIT=0|1`](#install_wait)
   - [`UPGRADE_CHECK=1|0`](#upgrade_check)
+  - [`VS2017=1|0`](#vs2017)
+  - [`VS2019=1|0`](#vs2019)
 - [Variables](#variables)
   - [`CTEST_OUTPUT_ON_FAILURE=1|0`](#ctest_output_on_failure)
   - [`QUIET=1|0`](#quiet)
@@ -382,10 +388,13 @@ Configuration variables:
 - <a id="cmake_generator"></a>[`CMAKE_GENERATOR=''|'...'`](#cmake_generator)
   [specifies which generator to use](https://cmake.org/cmake/help/latest/envvar/CMAKE_GENERATOR.html#envvar:CMAKE_GENERATOR).
 
-- <a id="cc"></a>[`CC=cc|gcc|clang|...`](#cc)
+- <a id="cmake_toolchain_file"></a>[`CMAKE_TOOLCHAIN_FILE=''|'...'`](#cmake_toolchain_file)
+  [specifies toolchain file to use](https://cmake.org/cmake/help/latest/variable/CMAKE_TOOLCHAIN_FILE.html).
+
+- <a id="cc"></a>[`CC=cc|gcc|clang|emcc|...`](#cc)
   [specifies which C compiler to use](https://cmake.org/cmake/help/latest/envvar/CC.html).
 
-- <a id="cxx"></a>[`CXX=c++|g++|clang++|...`](#cxx)
+- <a id="cxx"></a>[`CXX=c++|g++|clang++|emcc|...`](#cxx)
   [specifies which C++ compiler to use](https://cmake.org/cmake/help/latest/envvar/CXX.html).
 
 - <a id="clean"></a>[`CLEAN=0|1`](#clean) specifies whether the build directory
@@ -528,31 +537,45 @@ and [CI script](https://github.com/cppsm/cppsm-cli/blob/master/travis-ci) is
 provided to build and test both `Debug` and `Release` builds on various OS
 (Linux, OS X, Windows) and compiler configurations
 ([Clang](https://clang.llvm.org/), [GCC](https://gcc.gnu.org/),
-[Visual C++](https://docs.microsoft.com/en-us/cpp/)). Just add your project to
-Travis CI.
+[Visual C++](https://docs.microsoft.com/en-us/cpp/),
+[Emscripten](https://emscripten.org/)). Just add your project to Travis CI.
 
 - Linux
   - [Clang](https://clang.llvm.org/) (7)
   - [GCC](https://gcc.gnu.org/) (9)
+  - [Emscripten](https://emscripten.org/) (2)
 - OS X
   - Apple [Clang](https://clang.llvm.org/) (12)
   - [GCC](https://gcc.gnu.org/) (10)
+  - [Emscripten](https://emscripten.org/) (2)
 - Windows
   - [MinGW](http://www.mingw.org/) [GCC](https://gcc.gnu.org/) (8)
   - [Visual C++](https://docs.microsoft.com/en-us/cpp/) (2017, 2019)
 
 Configuration variables:
 
+- <a id="clang"></a>[`CLANG=1|0`](#clang) specifies whether to build with
+  [Clang](https://clang.llvm.org/). Set `CLANG=0` explicitly to skip building
+  with [Clang](https://clang.llvm.org/).
+
 - <a id="codecov"></a>[`CODECOV=0|1`](#codecov) specifies whether a code
   coverage test is executed and results are pushed to
   [Codecov](https://codecov.io/). Set `CODECOV=1` explicitly to enable code
   coverage.
 
+- <a id="emscripten"></a>[`EMSCRIPTEN=0|1`](#emscripten) specifies whether to
+  also build with [Emscripten](https://emscripten.org/). Set `EMSCRIPTEN=1`
+  explicitly to build with [Emscripten](https://emscripten.org/).
+
 - <a id="format_check"></a>[`FORMAT_CHECK=1|0`](#format_check) specifies whether
   to check that source files are formatted as with
   [`cppsm format`](#cppsm-format). Set `FORMAT_CHECK=0` explicitly to disable
   the format check.
 
+- <a id="gcc"></a>[`GCC=1|0`](#gcc) specifies whether to build with
+  [GCC](https://gcc.gnu.org/). Set `GCC=0` explicitly to skip building with
+  [GCC](https://gcc.gnu.org/).
+
 - <a id="install_wait"></a>[`INSTALL_WAIT=0|1`](#install_wait) specifies whether
   installation of additional packages is performed concurrently with builds when
   possible. Set `INSTALL_WAIT=1` explicitly to wait for installations to
@@ -563,6 +586,16 @@ Configuration variables:
   and, if something is upgraded, tests are rerun. Set `UPGRADE_CHECK=0`
   explicitly to skip the upgrade and conditional rerun of tests.
 
+- <a id="vs2017"></a>[`VS2017=1|0`](#vs2017) specifies whether to build with
+  [Visual C++](https://docs.microsoft.com/en-us/cpp/) 2017. Set `VS2017=0`
+  explicitly to skip building with
+  [Visual C++](https://docs.microsoft.com/en-us/cpp/) 2017.
+
+- <a id="vs2019"></a>[`VS2019=1|0`](#vs2019) specifies whether to build with
+  [Visual C++](https://docs.microsoft.com/en-us/cpp/) 2019. Set `VS2019=0`
+  explicitly to skip building with
+  [Visual C++](https://docs.microsoft.com/en-us/cpp/) 2019.
+
 ## <a id="variables"></a> [≡](#contents) [Variables](#variables)
 
 Several environment variables can be set to change the default behavior of one