diff --git a/cmake/Toolchain-wasm32-web.cmake b/cmake/Toolchain-wasm32-web.cmake
new file mode 100644
index 0000000..f08a2c2
--- /dev/null
+++ b/cmake/Toolchain-wasm32-web.cmake
@@ -0,0 +1,32 @@
+
+set(CMAKE_SYSTEM_PROCESSOR "wasm32" CACHE STRING "" FORCE)
+set(CMAKE_SYSTEM_NAME "Emscripten" CACHE STRING "" FORCE)
+set(CMAKE_SYSTEM_VERSION 1)
+set(CMAKE_CROSSCOMPILING TRUE)
+set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS FALSE)
+set(UNIX 1)
+set(SYSTRIPLET "${CMAKE_SYSTEM_PROCESSOR}-unknown-emscripten" CACHE STRING "" FORCE)
+add_compile_definitions(_LIBCPP_ENABLE_EXPERIMENTAL)
+set(TOOLCHAIN_PATH "/" CACHE PATH "Path to toolchain native sysroot")
+SET(TARGET_SYSROOT_PATH "/" CACHE PATH "Path to toolchain target sysroot")
+
+find_program(EMCC NAMES emcc REQUIRED)
+find_program(EMPP NAMES em++ REQUIRED)
+find_program(EMAR NAMES emar REQUIRED)
+find_program(EMRANLIB NAMES emranlib REQUIRED)
+		
+SET(CMAKE_FORCE_C_COMPILER ${EMCC})
+SET(CMAKE_FORCE_CXX_COMPILER ${EMPP})
+SET(CMAKE_C_COMPILER ${CMAKE_FORCE_C_COMPILER})
+SET(CMAKE_CXX_COMPILER ${CMAKE_FORCE_CXX_COMPILER})
+set(CMAKE_CXX_COMPILER_AR ${EMAR})
+set(CMAKE_AR ${EMAR})
+set(CMAKE_CXX_COMPILER_RANLIB ${EMRANLIB})
+set(CMAKE_RANLIB ${EMRANLIB})
+
+add_compile_options( -mbulk-memory )
+add_compile_options(  -sUSE_BOOST_HEADERS=1)
+
+add_link_options( -sALLOW_MEMORY_GROWTH -sMAXIMUM_MEMORY=4294901760 )
+
+set(EMSCRIPTEN_ENV "web")
diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
new file mode 100644
index 0000000..174285f
--- /dev/null
+++ b/source/CMakeLists.txt
@@ -0,0 +1,34 @@
+
+cmake_minimum_required(VERSION 3.20)
+project(cppdecl)
+
+set(CMAKE_CXX_STANDARD 20)
+
+
+if(CMAKE_CXX_COMPILER MATCHES "/em\\+\\+(-[a-zA-Z0-9.])?$")
+  message(" * C++ compiler: Emscripten")
+  set(CMAKE_CXX_COMPILER_ID "Emscripten")
+  if ("${EMSCRIPTEN_ENV}" STREQUAL "web")
+  set(CMAKE_EXECUTABLE_SUFFIX ".html")
+	else()
+  set(CMAKE_EXECUTABLE_SUFFIX ".js")
+  endif()
+  set(CMAKE_CXX_BYTE_ORDER "LITTLE_ENDIAN")
+else()
+  message(" * C++ compiler: ${CMAKE_CXX_COMPILER_ID}")
+endif()
+
+if ("${EMSCRIPTEN_ENV}" STREQUAL "web")
+
+	add_executable(index cppdecl-shell.cpp )
+	target_include_directories(index PUBLIC ../include)
+	target_link_options(index PUBLIC  --shell-file ${CMAKE_SOURCE_DIR}/cppdecl-shell.html)
+	target_link_options(index PUBLIC -sEXPORTED_FUNCTIONS=_main,_malloc,_free -sEXPORTED_RUNTIME_METHODS=UTF8ToString,stringToUTF8,lengthBytesUTF8,ccall,cwrap)
+
+else()
+	add_executable(cppdecl repl.cpp)
+	target_include_directories(cppdecl PUBLIC ../include)
+
+	add_executable(tests tests.cpp)
+	target_include_directories(tests PUBLIC ../include)
+endif()
diff --git a/source/cppdecl-shell.cpp b/source/cppdecl-shell.cpp
new file mode 100644
index 0000000..9dcbd08
--- /dev/null
+++ b/source/cppdecl-shell.cpp
@@ -0,0 +1,134 @@
+#include "cppdecl/declarations/parse.h"
+#include "cppdecl/declarations/simplify.h"
+#include "cppdecl/declarations/to_string.h"
+#include "cppdecl/type_name.h"
+#include <emscripten/html5.h>
+#include <emscripten.h>
+#include <sstream>
+
+
+std::string escape_xml(std::string_view sv) {
+	std::string result;
+	result.reserve(sv.size());
+	for (size_t i = 0; i < sv.size(); i++) {
+		uint8_t c = sv[i];
+
+		if ((c < 32 and c != '\n') or c == 127) {
+			continue;
+		}
+		switch (c) {
+		case '<':
+			result += "&lt;";
+			break;
+		case '>':
+			result += "&gt;";
+			break;
+		case '&':
+			result += "&amp;";
+			break;
+		case '\n':
+			result += "<br/>\n";
+			break;
+		case '"':
+			result += "&quot;";
+			break;
+			//case ' ':
+			//	result += "&nbsp;";
+			break;
+		default:
+			result += c;
+		}
+	}
+	constexpr std::array<char8_t, 4> lre = {u8"\u202A"}; // Left-to-Right Embedding
+	constexpr std::array<char8_t, 4> rle = {u8"\u202B"}; // Right-to-Left Embedding
+	constexpr std::array<char8_t, 4> pdf = {u8"\u202C"}; // Pop Directional Formatting
+	constexpr std::array<char8_t, 4> lro = {u8"\u202D"}; // Left-to-Right Override
+	constexpr std::array<char8_t, 4> rlo = {u8"\u202E"}; // Right-to-Left Override
+	constexpr std::array<char8_t, 4> lri = {u8"\u2066"}; // Left-to-Right isolate
+	constexpr std::array<char8_t, 4> rli = {u8"\u2067"}; // Right-to-Left isolate
+	constexpr std::array<char8_t, 4> fsi = {u8"\u2068"}; // First Strong isolate
+	constexpr std::array<char8_t, 4> pdi = {u8"\u2069"}; // Pop Directional isolate
+
+	constexpr std::array<std::array<char8_t, 4>, 9> control = {lre, rle, pdf, lro, rlo, lri, rli, fsi, pdi};
+	for (auto& sec : control) {
+		auto bidi = std::string_view(reinterpret_cast<const char*>(sec.data()), sec.size() - 1);
+		auto pos = result.find(bidi);
+		while (pos != std::string::npos) {
+			result.replace(pos, sec.size(), "");
+			pos = result.find(bidi);
+		}
+	}
+	return result;
+}
+
+namespace cppdecl{
+void parseText(std::string_view input) {
+
+    auto ret = cppdecl::ParseDecl(input, cppdecl::ParseDeclFlags::accept_everything);
+	std::ostringstream out;
+
+        if (auto error = std::get_if<cppdecl::ParseError>(&ret))
+        {
+            out << "Parse error: " << error->message << '\n';
+        }
+        else
+        {
+            if (!input.empty())
+                out << "Unparsed junk at the end of input.\n";
+
+            auto &decl = std::get<cppdecl::MaybeAmbiguousDecl>(ret);
+
+            out << "\n--- Parsed to:\n";
+            out << cppdecl::ToString(decl, {}) << '\n';
+
+            cppdecl::MaybeAmbiguousDecl simplified_decl = decl;
+            cppdecl::Simplify(cppdecl::SimplifyFlags::all, simplified_decl);
+            if (simplified_decl != decl)
+            {
+                out << "\n--- Simplifies to:\n";
+                out << cppdecl::ToCode(simplified_decl, {}) << '\n';
+
+                out << "\n--- The simplified version parses to:\n";
+                out << cppdecl::ToString(simplified_decl, {}) << '\n';
+            }
+        }
+
+	auto demangled = out.str();
+	auto escaped = escape_xml(demangled);
+	escaped = demangled;
+	EM_ASM_({ document.getElementById('demangled').value = UTF8ToString($0, $1); }, escaped.data(), escaped.size());
+}
+}
+
+
+extern "C" {
+EMSCRIPTEN_KEEPALIVE
+void parseText(const char* name1, int nlength1) {
+	cppdecl::parseText(std::string_view(name1, nlength1));
+}
+}
+
+void init_loop(void*) {
+#ifdef __EMSCRIPTEN__
+	emscripten_cancel_main_loop();
+
+	EM_ASM_({
+		Module.demangleText = Module.cwrap('demangleText', null, [ 'number', 'number' ]);
+		is_emscripten_initialized = 1;
+		set_darkmode(darkmode);
+		if (pending_demangle) {
+			document.getElementById('mangled').value = pending_demangle;
+			demangle_text(pending_demangle);
+			pending_demangle = null;
+		}
+		
+	});
+
+#endif
+}
+
+int main(int, char**) {
+	
+	emscripten_set_main_loop_arg(init_loop, nullptr, 0, false);
+	return 0;
+}
diff --git a/source/cppdecl-shell.html b/source/cppdecl-shell.html
new file mode 100644
index 0000000..6b7de1a
--- /dev/null
+++ b/source/cppdecl-shell.html
@@ -0,0 +1,94 @@
+<!doctype html>
+<html lang="en-us">
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<!--
+<link href='./favicon.svg' rel='icon' type='image/svg+xml'>
+<link href='./favicon.svg' rel='shortcut icon' type='image/svg+xml'>
+-->
+<title>cppdecl</title>
+<link rel="stylesheet" href="style.css">
+</head>
+<body>
+<div id="header" class="header">
+  cppdecl
+</div>
+<div id="main" >
+    <div id="mangledDiv">
+        <form class="mangling_form" id="mangling_form">
+    <label for="mangled">mangled name:</label>
+<input type="text" maxLength="40" size="40" id="mangled" name="mangled" >
+<button type="button" id="demangleButton" onclick="demangle_text(document.getElementById('mangled').value)">demangle</button>
+</form>
+</div>
+<div id="demangledDiv">
+    <textarea readonly rows="4" cols="40" id="demangled" name="demangled">
+</textarea>
+</div>
+
+<script >
+    var is_emscripten_initialized = 0;
+    var pending_demangle=null;
+    var darkmode = 0;
+    document.addEventListener('DOMContentLoaded', (event) => {
+    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
+        document.body.classList.add('darkmode');
+        darkmode = 1;
+    } else {
+        document.body.classList.remove('darkmode');
+        darkmode = 0;
+    }
+
+    window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
+    if (event.matches) {
+        document.body.classList.add('darkmode');
+        darkmode = 1;
+    } else {
+        document.body.classList.remove('darkmode');
+        darkmode = 0;
+    }
+    
+});
+
+    window.addEventListener('load', function() {
+        let mangling_form = document.getElementById('mangling_form');
+        mangling_form.reset();
+        document.getElementById('demangled').value = '';
+        
+    });
+    const urlParams = new URLSearchParams(window.location.search);
+    const mangled = urlParams.get('mangled');
+    
+    if (mangled) {
+  
+        if (is_emscripten_initialized == 1) {
+            document.getElementById('mangled').value = mangled;
+            parse_text(mangled);
+        } else {
+            pending_demangle = mangled;
+        }
+        
+    }
+
+});
+
+
+
+function parse_text(mangled) {
+    
+    console.log("parse_text", mangled);
+    const mangledLength = lengthBytesUTF8(mangled) + 1;
+    const mangledPtr = _malloc(mangledLength);
+    stringToUTF8(mangled, mangledPtr, mangledLength);
+
+    Module.parseText(mangledPtr, mangledLength - 1);
+    _free(mangledPtr);
+}
+
+</script>
+{{{ SCRIPT }}}
+
+</body>
+</html>