diff --git a/eng/pipelines/common/global-build-job.yml b/eng/pipelines/common/global-build-job.yml
index 95d61c4d6c6a..c9f9f749e9fb 100644
--- a/eng/pipelines/common/global-build-job.yml
+++ b/eng/pipelines/common/global-build-job.yml
@@ -177,8 +177,8 @@ jobs:
           df -h
         displayName: Disk Usage before Build
 
-    - ${{ if and(eq(parameters.runtimeFlavor, 'coreclr'), eq(parameters.platform, 'browser_wasm_win')) }}:
       # Install Wasm dependencies: emscripten, LLVM, NodeJS
+    - ${{ if and(eq(parameters.runtimeFlavor, 'coreclr'), eq(parameters.archType, 'wasm')) }}:
       - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-emscripten.cmd $(Build.SourcesDirectory)\wasm-tools
         displayName: Install/activate emscripten
       - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-llvm.cmd $(Build.SourcesDirectory)\wasm-tools $(Build.SourcesDirectory) ${{ parameters.buildConfig }}
@@ -187,11 +187,7 @@ jobs:
         displayName: Install NodeJS
 
     - ${{ if and(eq(parameters.runtimeFlavor, 'coreclr'), eq(parameters.platform, 'wasi_wasm_win')) }}:
-      # Install Wasi Wasm dependencies: emscripten, LLVM, wasi-sdk
-      - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-emscripten.cmd $(Build.SourcesDirectory)\wasm-tools
-        displayName: Install/activate emscripten
-      - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-llvm.cmd $(Build.SourcesDirectory)\wasm-tools $(Build.SourcesDirectory) ${{ parameters.buildConfig }}
-        displayName: Install/build LLVM
+      # Install Wasi Wasm dependencies: wasi-sdk, wasmer
       - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-wasi-sdk.cmd $(Build.SourcesDirectory)\wasm-tools
         displayName: Install wasi-sdk
       - script: call $(Build.SourcesDirectory)/eng/pipelines/runtimelab/install-wasmer.cmd $(Build.SourcesDirectory)\wasm-tools
diff --git a/eng/pipelines/runtimelab/install-nodejs.ps1 b/eng/pipelines/runtimelab/install-nodejs.ps1
index 48a606739f44..4327ac43761c 100644
--- a/eng/pipelines/runtimelab/install-nodejs.ps1
+++ b/eng/pipelines/runtimelab/install-nodejs.ps1
@@ -1,5 +1,5 @@
 $InstallPath = $Args[0]
-$NodeJSVersion = "v18.16.0"
+$NodeJSVersion = "v20.2.0"
 $NodeJSInstallName = "node-$NodeJSVersion-win-x64"
 $NodeJSZipName = "$NodeJSInstallName.zip"
 
diff --git a/src/coreclr/nativeaot/Bootstrap/main.cpp b/src/coreclr/nativeaot/Bootstrap/main.cpp
index c713a1c1e08d..0d83602097ba 100644
--- a/src/coreclr/nativeaot/Bootstrap/main.cpp
+++ b/src/coreclr/nativeaot/Bootstrap/main.cpp
@@ -168,11 +168,12 @@ extern "C" int __managed__Main(int argc, char* argv[]);
 #else
 #define NATIVEAOT_ENTRYPOINT __managed__Startup
 extern "C" void __managed__Startup();
+
+#ifdef TARGET_WASI
 // _initialize is a function generated by the WASI SDK libc that calls the LLVM synthesized __wasm_call_ctors function for reactor components:
 // https://github.com/WebAssembly/wasi-libc/blob/9f51a7102085ec6a6ced5778f0864c9af9f50000/libc-bottom-half/crt/crt1-reactor.c#L7-L27
 // We define and call it for NATIVEAOT_DLL and TARGET_WASI to call all the global c++ static constructors.  This ensures the runtime is initialized
-// when calling into WebAssembly Component Model components
-#if defined(NATIVEAOT_DLL) && defined(TARGET_WASI)
+// when calling into WebAssembly Component Model components.
 extern "C" void _initialize();
 
 // CustomNativeMain programs are built using the same libbootstrapperdll as NATIVEAOT_DLL but wasi-libc will not provide an _initialize implementation,
@@ -181,13 +182,20 @@ __attribute__((weak)) void _initialize()
 {
 }
 
+// Guard the "_initialize" call so that well-behaving hosts do not get affected by this workaround.
+static bool g_CalledInitialize = false;
+struct WasiInitializationFlag { WasiInitializationFlag() { *(volatile bool*)&g_CalledInitialize = true; } };
+WasiInitializationFlag g_WasiInitializationFlag;
 #endif // TARGET_WASI
 #endif // !NATIVEAOT_DLL
 
 static int InitializeRuntime()
 {
 #if defined(NATIVEAOT_DLL) && defined(TARGET_WASI)
-    _initialize();
+    if (!g_CalledInitialize)
+    {
+        _initialize();
+    }
 #endif
 
     if (!RhInitialize())
diff --git a/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets b/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
index 389f7cef6408..ea046c82edf7 100644
--- a/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
+++ b/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
@@ -116,7 +116,7 @@ The .NET Foundation licenses this file to you under the MIT license.
     <WasmOptimizationSetting Condition="$(Optimize) == 'true' and $(OptimizationPreference) != 'Size' and '$(_targetOS)' == 'wasi'">-O2</WasmOptimizationSetting>
     <WasmOptimizationSetting Condition="$(Optimize) == 'true' and $(OptimizationPreference) == 'Size'">-Oz</WasmOptimizationSetting>
 
-    <IlcLlvmTarget Condition="'$(_targetOS)' == 'wasi'">wasm32-wasi</IlcLlvmTarget>
+    <IlcLlvmTarget Condition="'$(_targetOS)' == 'wasi'">wasm32-unknown-wasi</IlcLlvmTarget>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(IlcCompileDependsOn)'=='' and '$(NativeCompilationDuringPublish)' != 'false'">
@@ -371,10 +371,17 @@ The .NET Foundation licenses this file to you under the MIT license.
     </ItemGroup>
   </Target>
 
+  <Target Name="CheckWasmSdks">
+    <Error Text="Emscripten not found, not compiling to WebAssembly. To enable WebAssembly compilation, install Emscripten and ensure the EMSDK environment variable points to the directory containing upstream/emscripten/emcc.bat"
+           Condition="'$(EMSDK)' == ''" />
+    <Error Text="Wasi SDK not found, not compiling to WebAssembly. To enable WebAssembly compilation, install Wasi SDK and ensure the WASI_SDK_PATH environment variable points to the directory containing share/wasi-sysroot"
+           Condition="'$(WASI_SDK_PATH)' == '' and '$(_targetOS)' == 'wasi'" />
+  </Target>
+
   <Target Name="CompileWasmObjects"
       Inputs="@(LlvmObjects)"
       Outputs="@(LlvmObjects->'%(NativeObject)')"
-      DependsOnTargets="IlcCompile;GenerateResFile"
+      DependsOnTargets="IlcCompile;GenerateResFile;CheckWasmSdks"
       Condition="'$(NativeCodeGen)' == 'llvm'">
 
     <MakeDir Directories="$([System.IO.Path]::GetDirectoryName($(NativeBinary)))" />
@@ -393,7 +400,7 @@ The .NET Foundation licenses this file to you under the MIT license.
     </PropertyGroup>
 
    <PropertyGroup Condition="'$(_targetOS)' == 'wasi'">
-      <CompileWasmArgs>-fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -disable-lsr --sysroot=&quot;$(WASI_SDK_PATH)/share/wasi-sysroot&quot; -target wasm32-wasi -c</CompileWasmArgs>
+      <CompileWasmArgs>-fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -disable-lsr --sysroot=&quot;$(WASI_SDK_PATH)/share/wasi-sysroot&quot; -target $(IlcLlvmTarget) -c</CompileWasmArgs>
       <CompileWasmArgs>$(CompileWasmArgs) $(WasmOptimizationSetting)</CompileWasmArgs>
       <CompileWasmArgs Condition="'$(NativeDebugSymbols)' == 'true'">$(CompileWasmArgs) -g3</CompileWasmArgs>
 
@@ -413,11 +420,7 @@ The .NET Foundation licenses this file to you under the MIT license.
       </ExecProjects>
     </ItemGroup>
 
-    <MSBuild Projects="@(ExecProjects)" BuildInParallel="true" Condition="'$(EMSDK)' != ''" />
-    <Message Text="Emscripten not found, not linking WebAssembly. To enable WebAssembly linking, install Emscripten and ensure the EMSDK environment variable points to the directory containing upstream/emscripten/emcc.bat"
-             Condition="'$(EMSDK)' == '' and '$(_targetOS)' == 'browser'" />
-    <Message Text="Wasi SDK not found, not linking WebAssembly. To enable WebAssembly linking, install Wasi SDK and ensure the WASI_SDK_PATH environment variable points to the directory containing share/wasi-sysroot"
-             Condition="'$(WASI_SDK_PATH)' == '' and '$(_targetOS)' == 'wasi'" />
+    <MSBuild Projects="@(ExecProjects)" BuildInParallel="true" />
   </Target>
 
   <Target Name="LinkNativeSingle" Condition="'$(_targetOS)' != 'browser' and '$(_targetOS)' != 'wasi'"
@@ -522,12 +525,19 @@ The .NET Foundation licenses this file to you under the MIT license.
       <CustomLinkerArg Condition="'$(WasmEnableExceptionHandling)' == 'true'" Include="-fwasm-exceptions" />
     </ItemGroup>
 
+    <!-- wasm-ld only supports listing exports on the command line -->
+    <ReadLinesFromFile File="$(ExportsFile)" Condition="'$(_targetOS)' == 'wasi' and '$(ExportsFile)' != ''">
+      <Output TaskParameter="Lines" ItemName="CustomLinkerArgExport" />
+    </ReadLinesFromFile>
+
     <ItemGroup Condition ="'$(_targetOS)' == 'wasi'" >
       <!-- Wasi has lots of undefined symbols currently, mostly globalization -->
       <CustomLinkerArg Include="-Wl,--unresolved-symbols=ignore-all -lstdc++ -Wl,--error-limit=0" />
       <CustomLinkerArg Include="--sysroot=&quot;$(WASI_SDK_PATH.Replace(&quot;\&quot;, &quot;/&quot;))/share/wasi-sysroot&quot;" />
       <CustomLinkerArg Include="-Wl,--max-memory=2147483648" />
       <CustomLinkerArg Include="-lwasi-emulated-process-clocks -lwasi-emulated-signal -lwasi-emulated-mman -lwasi-emulated-getpid" />
+      <CustomLinkerArg Include="-mexec-model=reactor" Condition="'$(NativeLib)' == 'Shared'" />
+      <CustomLinkerArg Include="@(CustomLinkerArgExport->'-Wl,--export=%(Identity)')" />
     </ItemGroup>
 
     <ItemGroup>
@@ -535,13 +545,7 @@ The .NET Foundation licenses this file to you under the MIT license.
     </ItemGroup>
 
     <WriteLinesToFile File="$(NativeIntermediateOutputPath)link.rsp" Lines="@(CustomLinkerArg)" Overwrite="true" Encoding="utf-8" />
-
-    <Exec Command="$(WasmLinkerPath) @$(NativeIntermediateOutputPath)link.rsp $(EmccExtraArgs)" 
-          Condition="('$(_targetOS)' == 'browser' and '$(EMSDK)' != '') or ('$(_targetOS)' == 'wasi' and '$(WASI_SDK_PATH)' != '')" />
-    <Message Text="Emscripten not found, not linking WebAssembly. To enable WebAssembly linking, install Emscripten and ensure the EMSDK environment variable points to the directory containing upstream/emscripten/emcc.bat"
-             Condition="'$(NativeCodeGen)' == 'llvm' and '$(_targetOS)' == 'browser'and '$(EMSDK)' == ''" Importance="High" />
-    <Message Text="Wasi SDK not found, not linking WebAssembly. To enable WebAssembly linking, install the Wasi SDK and ensure the WASI_SDK_PATH environment variable points to the directory containing share/wasi-sysroot"
-             Condition="'$(NativeCodeGen)' == 'llvm' and '$(_targetOS)' == 'wasi'and '$(WASI_SDK_PATH)' == ''" Importance="High" />
+    <Exec Command="$(WasmLinkerPath) @$(NativeIntermediateOutputPath)link.rsp $(EmccExtraArgs)" />
   </Target>
 
   <Target Name="LinkNative"
diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/ExportsFileWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/ExportsFileWriter.cs
index 4ea8ab29bf79..d02902e247de 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/ExportsFileWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/ExportsFileWriter.cs
@@ -37,11 +37,16 @@ public void EmitExportedMethods()
                     foreach (var method in _methods)
                         streamWriter.WriteLine($"   {method.GetUnmanagedCallersOnlyExportName()}");
                 }
-                else if(_context.Target.IsOSXLike || _context.Target.OperatingSystem == TargetOS.Browser)
+                else if (_context.Target.IsOSXLike || _context.Target.OperatingSystem == TargetOS.Browser)
                 {
                     foreach (var method in _methods)
                         streamWriter.WriteLine($"_{method.GetUnmanagedCallersOnlyExportName()}");
                 }
+                else if (_context.Target.OperatingSystem == TargetOS.Wasi)
+                {
+                    foreach (var method in _methods)
+                        streamWriter.WriteLine(method.GetUnmanagedCallersOnlyExportName());
+                }
                 else
                 {
                     streamWriter.WriteLine("V1.0 {");
diff --git a/src/tests/Common/dirs.proj b/src/tests/Common/dirs.proj
index d00d8426235c..bbd42f88bb17 100644
--- a/src/tests/Common/dirs.proj
+++ b/src/tests/Common/dirs.proj
@@ -22,7 +22,7 @@
     </ItemGroup>
 
     <ItemGroup Condition="'$(TestBuildMode)' == 'nativeaot' and '$(TargetArchitecture)' == 'wasm'">
-      <DisabledProjects Include="$(TestRoot)nativeaot\SmokeTests\SharedLibrary\SharedLibrary.csproj" />
+      <DisabledProjects Include="$(TestRoot)nativeaot\SmokeTests\SharedLibrary\SharedLibrary.csproj" Condition="'$(TargetOS)' == 'browser'" />
       <DisabledProjects Include="$(TestRoot)nativeaot\GenerateUnmanagedEntryPoints\GenerateUnmanagedEntryPoints.csproj" />
 
       <!-- Manual test. -->
diff --git a/src/tests/Common/scripts/nativeaottest.cmd b/src/tests/Common/scripts/nativeaottest.cmd
index cf91085db3fb..09a52929d4ba 100644
--- a/src/tests/Common/scripts/nativeaottest.cmd
+++ b/src/tests/Common/scripts/nativeaottest.cmd
@@ -16,6 +16,11 @@ set __JsFileName=%2
 set __JsFileName=%__JsFileName:~0,-4%.js
 set __JsFilePath=%1\native\%__JsFileName%
 
+REM also probe for .mjs
+if not exist %__JsFilePath% (
+  set __JsFilePath=%__JsFilePath:~0,-3%.mjs
+)
+
 set __WasmFileName=%2
 set __WasmFileName=%__WasmFileName:~0,-4%.wasm
 set __WasmFilePath=%1native\%__WasmFileName%
diff --git a/src/tests/nativeaot/SmokeTests/HelloWasm/HelloWasm.csproj b/src/tests/nativeaot/SmokeTests/HelloWasm/HelloWasm.csproj
index 1a8ad38bada3..d107e58e3f78 100644
--- a/src/tests/nativeaot/SmokeTests/HelloWasm/HelloWasm.csproj
+++ b/src/tests/nativeaot/SmokeTests/HelloWasm/HelloWasm.csproj
@@ -2,7 +2,6 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <CLRTestKind>BuildAndRun</CLRTestKind>
-    <CLRTestPriority>0</CLRTestPriority>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 
     <!-- IL3049 warns about mismatched signatures; we are intentionally testing they are handled correctly
diff --git a/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibrary.csproj b/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibrary.csproj
index 09b36ffbd9fb..eedb3c384fbd 100644
--- a/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibrary.csproj
+++ b/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibrary.csproj
@@ -5,26 +5,36 @@
     <CLRTestPriority>0</CLRTestPriority>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <NativeLib>Shared</NativeLib>
+
+    <WasiReactorTestUsingNodeJS Condition="'$(TargetOS)' == 'wasi'">true</WasiReactorTestUsingNodeJS>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="SharedLibrary.cs" />
+  </ItemGroup>
+
   <PropertyGroup>
+    <NativeExtension Condition="'$(WasiReactorTestUsingNodeJS)' == 'true'">.mjs</NativeExtension>
+    <NativeExtension Condition="'$(TargetOS)' == 'windows'">.exe</NativeExtension>
+
     <CLRTestBatchPreCommands><![CDATA[
 $(CLRTestBatchPreCommands)
 mkdir native 2>nul
-copy /y SharedLibraryDriver.exe native\SharedLibrary.exe
+copy /y SharedLibraryDriver$(NativeExtension) native\SharedLibrary$(NativeExtension)
 ]]></CLRTestBatchPreCommands>
 
     <CLRTestBashPreCommands><![CDATA[
 $(CLRTestBashPreCommands)
 mkdir -p native
-cp SharedLibraryDriver native/SharedLibrary
+cp SharedLibraryDriver$(NativeExtension) native/SharedLibrary$(NativeExtension)
 ]]></CLRTestBashPreCommands>
   </PropertyGroup>
 
-  <ItemGroup>
-    <Compile Include="SharedLibrary.cs" />
-  </ItemGroup>
-  <ItemGroup>
+  <ItemGroup Condition="'$(WasiReactorTestUsingNodeJS)' != 'true'">
     <CMakeProjectReference Include="CMakeLists.txt" />
   </ItemGroup>
+
+  <ItemGroup Condition="'$(WasiReactorTestUsingNodeJS)' == 'true'">
+    <Content Include="SharedLibraryDriver.mjs" CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
 </Project>
diff --git a/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibraryDriver.mjs b/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibraryDriver.mjs
new file mode 100644
index 000000000000..604d6219bf37
--- /dev/null
+++ b/src/tests/nativeaot/SmokeTests/SharedLibrary/SharedLibraryDriver.mjs
@@ -0,0 +1,39 @@
+import { readFile } from 'node:fs/promises';
+import { WASI } from 'wasi';
+import { argv, env } from 'node:process';
+
+const wasi = new WASI({
+  version: 'preview1',
+  args: argv,
+  env
+});
+
+const wasm = await WebAssembly.compile(  
+  await readFile(new URL("./SharedLibrary.wasm", import.meta.url)),
+);
+
+const instance = await WebAssembly.instantiate(wasm, wasi.getImportObject());
+
+wasi.initialize(instance);
+
+if (instance.exports.ReturnsPrimitiveInt() != 10)
+    process.exit(1);
+
+if (instance.exports.ReturnsPrimitiveBool() != 1)
+    process.exit(2);
+
+if (instance.exports.ReturnsPrimitiveChar() != 97) // 'a'
+    process.exit(3);
+
+// As long as no unmanaged exception is thrown managed class loaders were initialized successfully.
+instance.exports.EnsureManagedClassLoaders();
+
+// #if !CODEGEN_WASI - for some reason tries to create a background thread?
+// if (instance.exports.CheckSimpleGCCollect() != 100)
+//     process.exit(4);
+
+// #if !CODEGEN_WASI - enable when we support exception handling
+// if (instance.exports.CheckSimpleExceptionHandling() != 100)
+//    process.exit(5);
+
+process.exit(100);