diff --git a/converter/build.gradle b/converter/build.gradle
deleted file mode 100644
index a3661b7..0000000
--- a/converter/build.gradle
+++ /dev/null
@@ -1,54 +0,0 @@
-
-plugins {
-    id "java"
-    id "eclipse"
-}
-
-version = "${rootProject.fw_version}${-> getVersionSuffix()}"
-group = "io.github.zekerzhayard"
-archivesBaseName = rootProject.name + "Converter"
-
-sourceCompatibility = targetCompatibility = 1.8
-compileJava {
-    sourceCompatibility = targetCompatibility = 1.8
-}
-
-configurations {
-    provided {
-        implementation.extendsFrom provided
-    }
-}
-
-repositories {
-    mavenCentral()
-}
-
-dependencies {
-    compileOnly "com.google.code.gson:gson:2.8.7"
-    provided rootProject
-}
-
-jar {
-    manifest.attributes rootProject.jar.manifest.attributes
-    manifest.attributes([
-            "Main-Class": "io.github.zekerzhayard.forgewrapper.converter.Main"
-    ])
-
-    from configurations.provided.files.collect {
-        duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-        zipTree(it)
-    }
-}
-
-processResources {
-    inputs.property "version", project.version
-    from(sourceSets.main.resources.srcDirs) {
-        duplicatesStrategy = DuplicatesStrategy.INCLUDE
-        include "patches/net.minecraftforge.json"
-        expand "version": project.version
-    }
-    from(sourceSets.main.resources.srcDirs) {
-        duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-        exclude "patches/net.minecraftforge.json"
-    }
-}
diff --git a/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Converter.java b/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Converter.java
deleted file mode 100644
index ade550f..0000000
--- a/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Converter.java
+++ /dev/null
@@ -1,157 +0,0 @@
-package io.github.zekerzhayard.forgewrapper.converter;
-
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.nio.file.StandardCopyOption;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipFile;
-
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonNull;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
-
-public class Converter {
-    public static void convert(Path installerPath, Path targetDir, Path multimcDir) throws Exception {
-        JsonObject installer = getJsonFromZip(installerPath, "version.json");
-        JsonObject installProfile = getJsonFromZip(installerPath, "install_profile.json");
-        List<String> arguments = getAdditionalArgs(installer);
-        String mcVersion = arguments.get(arguments.indexOf("--fml.mcVersion") + 1);
-        String forgeVersion = arguments.get(arguments.indexOf("--fml.forgeVersion") + 1);
-        String forgeFullVersion = "forge-" + mcVersion + "-" + forgeVersion;
-        StringBuilder wrapperVersion = new StringBuilder();
-
-        JsonObject pack = convertPackJson(mcVersion);
-        JsonObject patches = convertPatchesJson(installer, installProfile, mcVersion, forgeVersion, wrapperVersion);
-
-        Files.createDirectories(targetDir);
-
-        // Copy mmc-pack.json and instance.cfg to <instance> folder.
-        Path instancePath = targetDir.resolve(forgeFullVersion);
-        Files.createDirectories(instancePath);
-        Files.copy(new ByteArrayInputStream(pack.toString().getBytes(StandardCharsets.UTF_8)), instancePath.resolve("mmc-pack.json"), StandardCopyOption.REPLACE_EXISTING);
-        Files.copy(new ByteArrayInputStream(("InstanceType=OneSix\nname=" + forgeFullVersion).getBytes(StandardCharsets.UTF_8)), instancePath.resolve("instance.cfg"), StandardCopyOption.REPLACE_EXISTING);
-
-        // Copy ForgeWrapper to <instance>/libraries folder.
-        Path librariesPath = instancePath.resolve("libraries");
-        Files.createDirectories(librariesPath);
-        Files.copy(Paths.get(Converter.class.getProtectionDomain().getCodeSource().getLocation().toURI()), librariesPath.resolve(wrapperVersion.toString()), StandardCopyOption.REPLACE_EXISTING);
-
-        // Copy net.minecraftforge.json to <instance>/patches folder.
-        Path patchesPath = instancePath.resolve("patches");
-        Files.createDirectories(patchesPath);
-        Files.copy(new ByteArrayInputStream(patches.toString().getBytes(StandardCharsets.UTF_8)), patchesPath.resolve("net.minecraftforge.json"), StandardCopyOption.REPLACE_EXISTING);
-
-        // Copy forge installer to MultiMC/libraries/net/minecraftforge/forge/<mcVersion>-<forgeVersion> folder.
-        if (multimcDir != null) {
-            Path targetInstallerPath = multimcDir.resolve("libraries").resolve("net").resolve("minecraftforge").resolve("forge").resolve(forgeVersion);
-            Files.createDirectories(targetInstallerPath);
-            Files.copy(installerPath, targetInstallerPath.resolve(forgeFullVersion + "-installer.jar"), StandardCopyOption.REPLACE_EXISTING);
-        }
-    }
-
-    public static List<String> getAdditionalArgs(JsonObject installer) {
-        List<String> args = new ArrayList<>();
-        getElement(installer.getAsJsonObject("arguments"), "game").getAsJsonArray().iterator().forEachRemaining(je -> args.add(je.getAsString()));
-        return args;
-    }
-
-    public static JsonObject getJsonFromZip(Path path, String json) {
-        try {
-            ZipFile zf = new ZipFile(path.toFile());
-            ZipEntry versionFile = zf.getEntry(json);
-            if (versionFile == null) {
-                throw new RuntimeException("The zip file is invalid!");
-            }
-            InputStreamReader isr = new InputStreamReader(zf.getInputStream(versionFile), StandardCharsets.UTF_8);
-            return JsonParser.parseReader(isr).getAsJsonObject();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    // Convert mmc-pack.json:
-    //   - Replace Minecraft version
-    private static JsonObject convertPackJson(String mcVersion) {
-        JsonObject pack = JsonParser.parseReader(new InputStreamReader(Converter.class.getResourceAsStream("/mmc-pack.json"))).getAsJsonObject();
-
-        for (JsonElement component : getElement(pack, "components").getAsJsonArray()) {
-            JsonObject componentObject = component.getAsJsonObject();
-            JsonElement version = getElement(componentObject, "version");
-            if (!version.isJsonNull() && getElement(componentObject, "uid").getAsString().equals("net.minecraft")) {
-                componentObject.addProperty("version", mcVersion);
-            }
-        }
-        return pack;
-    }
-
-    // Convert patches/net.minecraftforge.json:
-    //   - Add libraries
-    //   - Add forge-launcher url
-    //   - Replace Minecraft & Forge versions
-    private static JsonObject convertPatchesJson(JsonObject installer, JsonObject installProfile, String mcVersion, String forgeVersion, StringBuilder wrapperVersion) {
-        JsonObject patches = JsonParser.parseReader(new InputStreamReader(Converter.class.getResourceAsStream("/patches/net.minecraftforge.json"))).getAsJsonObject();
-        JsonArray mavenFiles = getElement(patches, "mavenFiles").getAsJsonArray();
-        JsonArray libraries = getElement(patches, "libraries").getAsJsonArray();
-
-        String minecraftArguments = String.join(" ", getElement(patches, "minecraftArguments").getAsString(), "--username ${auth_player_name} --version ${version_name} --gameDir ${game_directory} --assetsDir ${assets_root} --assetIndex ${assets_index_name} --uuid ${auth_uuid} --accessToken ${auth_access_token} --userType ${user_type} --versionType ${version_type}", String.join(" ", getAdditionalArgs(installer))).trim();
-        patches.addProperty("minecraftArguments", minecraftArguments);
-
-        for (JsonElement mavenFile : mavenFiles) {
-            String name = getElement(mavenFile.getAsJsonObject(), "name").getAsString();
-            mavenFile.getAsJsonObject().addProperty("name", name.replace("{VERSION}", mcVersion).replace("{FORGE_VERSION}", forgeVersion));
-        }
-        for (JsonElement lib : libraries) {
-            String name = getElement(lib.getAsJsonObject(), "name").getAsString();
-            if (name.startsWith("io.github.zekerzhayard:ForgeWrapper:")) {
-                wrapperVersion.append(getElement(lib.getAsJsonObject(), "MMC-filename").getAsString());
-            }
-        }
-        Map<String, String> additionalUrls = new HashMap<>();
-        String path = String.format("net/minecraftforge/forge/%s-%s/forge-%s-%s", mcVersion, forgeVersion, mcVersion, forgeVersion);
-        additionalUrls.put(path + "-universal.jar", "https://maven.minecraftforge.net/" + path + "-universal.jar");
-        transformLibraries(getElement(installProfile, "libraries").getAsJsonArray(), mavenFiles, additionalUrls);
-        additionalUrls.clear();
-        additionalUrls.put(path + ".jar", "https://maven.minecraftforge.net/" + path + "-launcher.jar");
-        transformLibraries(getElement(installer, "libraries").getAsJsonArray(), libraries, additionalUrls);
-
-        patches.addProperty("version", forgeVersion);
-        for (JsonElement require : getElement(patches, "requires").getAsJsonArray()) {
-            JsonObject requireObject = require.getAsJsonObject();
-            if (getElement(requireObject, "uid").getAsString().equals("net.minecraft")) {
-                requireObject.addProperty("equals", mcVersion);
-            }
-        }
-        return patches;
-    }
-
-    private static JsonElement getElement(JsonObject object, String property) {
-        Optional<Map.Entry<String, JsonElement>> first = object.entrySet().stream().filter(e -> e.getKey().equals(property)).findFirst();
-        if (first.isPresent()) {
-            return first.get().getValue();
-        }
-        return JsonNull.INSTANCE;
-    }
-
-    private static void transformLibraries(JsonArray source, JsonArray target, Map<String, String> additionalUrls) {
-        for (JsonElement lib : source) {
-            JsonObject artifact = getElement(getElement(lib.getAsJsonObject(), "downloads").getAsJsonObject(), "artifact").getAsJsonObject();
-            String path = getElement(artifact, "path").getAsString();
-            if (additionalUrls.containsKey(path)) {
-                artifact.getAsJsonObject().addProperty("url", additionalUrls.get(path));
-            }
-            target.add(lib);
-        }
-    }
-}
diff --git a/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Main.java b/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Main.java
deleted file mode 100644
index 83ecdf9..0000000
--- a/converter/src/main/java/io/github/zekerzhayard/forgewrapper/converter/Main.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package io.github.zekerzhayard.forgewrapper.converter;
-
-import java.net.URL;
-import java.net.URLClassLoader;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.util.HashMap;
-
-public class Main {
-    public static void main(String[] args) {
-        Path installer = null, instance = Paths.get("."), multimc = null;
-        try {
-            HashMap<String, String> argsMap = parseArgs(args);
-            installer = Paths.get(argsMap.get("--installer"));
-            if (argsMap.containsKey("--instance")) {
-                instance = Paths.get(argsMap.get("--instance"));
-                multimc = instance.getParent();
-            }
-        } catch (Exception e) {
-            System.out.println("Invalid arguments! Use: java -jar <ForgeWrapper.jar> --installer=<forge-installer.jar> [--instance=<instance-path>]");
-            throw new RuntimeException(e);
-        }
-
-        try {
-            URLClassLoader ucl = URLClassLoader.newInstance(new URL[] {
-                Converter.class.getProtectionDomain().getCodeSource().getLocation(),
-                installer.toUri().toURL()
-            }, null);
-            ucl.loadClass("io.github.zekerzhayard.forgewrapper.converter.Converter").getMethod("convert", Path.class, Path.class, Path.class).invoke(null, installer, instance, multimc);
-            System.out.println("Successfully install Forge for MultiMC!");
-        } catch (Exception e) {
-            System.out.println("Failed to install Forge!");
-            throw new RuntimeException(e);
-        }
-    }
-
-    /**
-     * @return installer -- The path of forge installer.<br/>
-     * instance -- The instance folder of MultiMC.<br/>
-     * cursepack -- The version of cursepacklocator.<br/>
-     */
-    private static HashMap<String, String> parseArgs(String[] args) {
-        HashMap<String, String> map = new HashMap<>();
-        for (String arg : args) {
-            String[] params = arg.split("=", 2);
-            map.put(params[0], params[1]);
-        }
-        if (!map.containsKey("--installer")) {
-            throw new IllegalArgumentException();
-        }
-        return map;
-    }
-}
diff --git a/converter/src/main/resources/mmc-pack.json b/converter/src/main/resources/mmc-pack.json
deleted file mode 100644
index 87db08a..0000000
--- a/converter/src/main/resources/mmc-pack.json
+++ /dev/null
@@ -1,13 +0,0 @@
-{
-  "formatVersion": 1,
-  "components": [
-    {
-      "important": true,
-      "uid": "net.minecraft",
-      "version": "{VERSION}"
-    },
-    {
-      "uid": "net.minecraftforge"
-    }
-  ]
-}
diff --git a/converter/src/main/resources/patches/net.minecraftforge.json b/converter/src/main/resources/patches/net.minecraftforge.json
deleted file mode 100644
index 4fac6aa..0000000
--- a/converter/src/main/resources/patches/net.minecraftforge.json
+++ /dev/null
@@ -1,28 +0,0 @@
-{
-  "formatVersion": 1,
-  "mainClass": "io.github.zekerzhayard.forgewrapper.installer.Main",
-  "minecraftArguments": "",
-  "name": "Forge",
-  "requires": [
-    {
-      "equals": "{VERSION}",
-      "uid": "net.minecraft"
-    }
-  ],
-  "type": "release",
-  "uid": "net.minecraftforge",
-  "version": "{FORGE_VERSION}",
-  "mavenFiles": [
-    {
-      "name": "net.minecraftforge:forge:{VERSION}-{FORGE_VERSION}:installer",
-      "url": "https://maven.minecraftforge.net/"
-    }
-  ],
-  "libraries": [
-    {
-      "name": "io.github.zekerzhayard:ForgeWrapper:${version}",
-      "MMC-hint": "local",
-      "MMC-filename": "ForgeWrapper-${version}.jar"
-    }
-  ]
-}
diff --git a/gradle.properties b/gradle.properties
index 677a8cd..6202251 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
 
 org.gradle.daemon = false
 
-fw_version = mmc3
+fw_version = mmc4
diff --git a/jigsaw/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java b/jigsaw/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
index 9a49d7f..e15d39c 100644
--- a/jigsaw/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
+++ b/jigsaw/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
@@ -9,6 +9,7 @@ import java.lang.module.ModuleFinder;
 import java.lang.module.ModuleReference;
 import java.lang.module.ResolvedModule;
 import java.lang.reflect.Field;
+import java.net.URL;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.HashMap;
@@ -159,6 +160,15 @@ public class ModuleUtil {
         }
     }
 
+    public static void setupClassPath(Path libraryDir, List<String> paths) throws Throwable {
+        Class<?> urlClassPathClass = Class.forName("jdk.internal.loader.URLClassPath");
+        Object ucp = IMPL_LOOKUP.findGetter(Class.forName("jdk.internal.loader.BuiltinClassLoader"), "ucp", urlClassPathClass).invokeWithArguments(ClassLoader.getSystemClassLoader());
+        MethodHandle addURLMH = IMPL_LOOKUP.findVirtual(urlClassPathClass, "addURL", MethodType.methodType(void.class, URL.class));
+        for (String path : paths) {
+            addURLMH.invokeWithArguments(ucp, libraryDir.resolve(path).toUri().toURL());
+        }
+    }
+
     // ForgeWrapper need some extra settings to invoke BootstrapLauncher.
     public static Class<?> setupBootstrapLauncher(Class<?> mainClass) throws Throwable {
         if (!mainClass.getModule().isOpen(mainClass.getPackageName(), ModuleUtil.class.getModule())) {
diff --git a/legacy/build.gradle b/legacy/build.gradle
index 8824390..4778335 100644
--- a/legacy/build.gradle
+++ b/legacy/build.gradle
@@ -4,6 +4,11 @@ plugins {
     id "eclipse"
 }
 
+sourceCompatibility = targetCompatibility = 1.8
+compileJava {
+    sourceCompatibility = targetCompatibility = 1.8
+}
+
 repositories {
     mavenCentral()
     maven {
diff --git a/settings.gradle b/settings.gradle
index 7bda9a2..34c563d 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,6 +1,5 @@
 rootProject.name = 'ForgeWrapper'
 
 include 'common'
-include 'converter'
 include 'legacy'
 include 'jigsaw'
diff --git a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Bootstrap.java b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Bootstrap.java
index 2740b76..3604371 100644
--- a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Bootstrap.java
+++ b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Bootstrap.java
@@ -15,6 +15,15 @@ public class Bootstrap {
         }
         jvmArgs = replacedJvmArgs;
 
+        // Remove NewLaunch.jar from property to prevent Forge from adding it to the module path
+        StringBuilder newCP = new StringBuilder();
+        for (String path : System.getProperty("java.class.path").split(File.pathSeparator)) {
+            if (!path.endsWith("NewLaunch.jar")) {
+                newCP.append(path).append(File.pathSeparator);
+            }
+        }
+        System.setProperty("java.class.path", newCP.substring(0, newCP.length() - 1));
+
         String modulePath = null;
         List<String> addExports = new ArrayList<>();
         List<String> addOpens = new ArrayList<>();
diff --git a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Main.java b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Main.java
index 7134ba5..37876a6 100644
--- a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Main.java
+++ b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/Main.java
@@ -15,22 +15,31 @@ import io.github.zekerzhayard.forgewrapper.installer.util.ModuleUtil;
 
 public class Main {
     public static void main(String[] args) throws Throwable {
+        // --fml.neoForgeVersion 20.2.20-beta --fml.fmlVersion 1.0.2 --fml.mcVersion 1.20.2 --fml.neoFormVersion 20231019.002635 --launchTarget forgeclient
+
         List<String> argsList = Stream.of(args).collect(Collectors.toList());
+        // NOTE: this is only true for NeoForge versions past 20.2.x
+        // early versions of NeoForge (for 1.20.1) are not supposed to be covered here
+        boolean isNeoForge = argsList.contains("--fml.neoForgeVersion");
+
         String mcVersion = argsList.get(argsList.indexOf("--fml.mcVersion") + 1);
-        String forgeVersion = argsList.get(argsList.indexOf("--fml.forgeVersion") + 1);
-        String forgeFullVersion = mcVersion + "-" + forgeVersion;
+        String forgeGroup = argsList.contains("--fml.forgeGroup") ? argsList.get(argsList.indexOf("--fml.forgeGroup") + 1) : "net.neoforged";
+        String forgeArtifact = isNeoForge ? "neoforge" : "forge";
+        String forgeVersionKey = isNeoForge ? "--fml.neoForgeVersion" : "--fml.forgeVersion";
+        String forgeVersion = argsList.get(argsList.indexOf(forgeVersionKey) + 1);
+        String forgeFullVersion = isNeoForge ? forgeVersion : mcVersion + "-" + forgeVersion;
 
         IFileDetector detector = DetectorLoader.loadDetector();
         try {
-            Bootstrap.bootstrap(detector.getJvmArgs(forgeFullVersion), detector.getMinecraftJar(mcVersion).getFileName().toString(), detector.getLibraryDir().toAbsolutePath().toString());
+            Bootstrap.bootstrap(detector.getJvmArgs(forgeGroup, forgeArtifact, forgeFullVersion), detector.getMinecraftJar(mcVersion).getFileName().toString(), detector.getLibraryDir().toAbsolutePath().toString());
         } catch (Throwable ignored) {
             // Avoid this bunch of hacks that nuke the whole wrapper.
         }
-        if (!detector.checkExtraFiles(forgeFullVersion)) {
+        if (!detector.checkExtraFiles(forgeGroup, forgeArtifact, forgeFullVersion)) {
             System.out.println("Some extra libraries are missing! Running the installer to generate them now.");
 
             // Check installer jar.
-            Path installerJar = detector.getInstallerJar(forgeFullVersion);
+            Path installerJar = detector.getInstallerJar(forgeGroup, forgeArtifact, forgeFullVersion);
             if (!IFileDetector.isFile(installerJar)) {
                 throw new RuntimeException("Unable to detect the forge installer!");
             }
@@ -53,7 +62,8 @@ public class Main {
             }
         }
 
-        Class<?> mainClass = ModuleUtil.setupBootstrapLauncher(Class.forName(detector.getMainClass(forgeFullVersion)));
+        ModuleUtil.setupClassPath(detector.getLibraryDir(), detector.getExtraLibraries(forgeGroup, forgeArtifact, forgeFullVersion));
+        Class<?> mainClass = ModuleUtil.setupBootstrapLauncher(Class.forName(detector.getMainClass(forgeGroup, forgeArtifact, forgeFullVersion)));
         mainClass.getMethod("main", String[].class).invoke(null, new Object[] { args });
     }
 }
diff --git a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/IFileDetector.java b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/IFileDetector.java
index cfb926e..c10a796 100644
--- a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/IFileDetector.java
+++ b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/IFileDetector.java
@@ -61,10 +61,12 @@ public interface IFileDetector {
     }
 
     /**
+     * @param forgeGroup Forge package group (e.g. net.minecraftforge).
+     * @param forgeArtifact Forge package artifact (e.g. forge).
      * @param forgeFullVersion Forge full version (e.g. 1.14.4-28.2.0).
      * @return The forge installer jar path. It can also be defined by JVM argument "-Dforgewrapper.installer=&lt;installer-path&gt;".
      */
-    default Path getInstallerJar(String forgeFullVersion) {
+    default Path getInstallerJar(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
         String installer = System.getProperty("forgewrapper.installer");
         if (installer != null) {
             return Paths.get(installer).toAbsolutePath();
@@ -85,12 +87,14 @@ public interface IFileDetector {
     }
 
     /**
+     * @param forgeGroup Forge package group (e.g. net.minecraftforge).
+     * @param forgeArtifact Forge package artifact (e.g. forge).
      * @param forgeFullVersion Forge full version (e.g. 1.14.4-28.2.0).
      * @return The list of jvm args.
      */
-    default List<String> getJvmArgs(String forgeFullVersion) {
-        return this.getDataFromInstaller(forgeFullVersion, "version.json", e -> {
-            JsonElement element = getElement(e.getAsJsonObject().getAsJsonObject("arguments"), "jvm");
+    default List<String> getJvmArgs(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        return this.getDataFromInstaller(forgeGroup, forgeArtifact, forgeFullVersion, "version.json", e -> {
+            JsonElement element = e.getAsJsonObject().get("arguments").getAsJsonObject().get("jvm");
             List<String> args = new ArrayList<>();
             if (!element.equals(JsonNull.INSTANCE)) {
                 element.getAsJsonArray().iterator().forEachRemaining(je -> args.add(je.getAsString()));
@@ -99,25 +103,42 @@ public interface IFileDetector {
         });
     }
 
+    default List<String> getExtraLibraries(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        return this.getDataFromInstaller(forgeGroup, forgeArtifact, forgeFullVersion, "version.json", e -> {
+            List<String> paths = new ArrayList<>();
+            e.getAsJsonObject().getAsJsonArray("libraries").iterator().forEachRemaining(je -> {
+                JsonObject artifact = je.getAsJsonObject().get("downloads").getAsJsonObject().get("artifact").getAsJsonObject();
+                if (artifact.get("url").getAsString().isEmpty()) {
+                    paths.add(artifact.get("path").getAsString());
+                }
+            });
+            return paths;
+        });
+    }
+
     /**
+     * @param forgeGroup Forge package group (e.g. net.minecraftforge).
+     * @param forgeArtifact Forge package artifact (e.g. forge).
      * @param forgeFullVersion Forge full version (e.g. 1.14.4-28.2.0).
      * @return The main class.
      */
-    default String getMainClass(String forgeFullVersion) {
-        return this.getDataFromInstaller(forgeFullVersion, "version.json", e -> e.getAsJsonObject().getAsJsonPrimitive("mainClass").getAsString());
+    default String getMainClass(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        return this.getDataFromInstaller(forgeGroup, forgeArtifact, forgeFullVersion, "version.json", e -> e.getAsJsonObject().getAsJsonPrimitive("mainClass").getAsString());
     }
 
     /**
+     * @param forgeGroup Forge package group (e.g. net.minecraftforge).
+     * @param forgeArtifact Forge package artifact (e.g. forge).
      * @param forgeFullVersion Forge full version (e.g. 1.14.4-28.2.0).
      * @return The json object in the-installer-jar-->install_profile.json-->data-->xxx-->client.
      */
-    default JsonObject getInstallProfileExtraData(String forgeFullVersion) {
-        return this.getDataFromInstaller(forgeFullVersion, "install_profile.json", e -> e.getAsJsonObject().getAsJsonObject("data"));
+    default JsonObject getInstallProfileExtraData(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        return this.getDataFromInstaller(forgeGroup, forgeArtifact, forgeFullVersion, "install_profile.json", e -> e.getAsJsonObject().getAsJsonObject("data"));
     }
 
     @SuppressWarnings("deprecation")
-    default <R> R getDataFromInstaller(String forgeFullVersion, String entry, Function<JsonElement, R> function) {
-        Path installer = this.getInstallerJar(forgeFullVersion);
+    default <R> R getDataFromInstaller(String forgeGroup, String forgeArtifact, String forgeFullVersion, String entry, Function<JsonElement, R> function) {
+        Path installer = this.getInstallerJar(forgeGroup, forgeArtifact, forgeFullVersion);
         if (isFile(installer)) {
             try (ZipFile zf = new ZipFile(installer.toFile())) {
                 ZipEntry ze = zf.getEntry(entry);
@@ -140,11 +161,13 @@ public interface IFileDetector {
 
     /**
      * Check all cached files.
+     * @param forgeGroup Forge package group (e.g. net.minecraftforge).
+     * @param forgeArtifact Forge package artifact (e.g. forge).
      * @param forgeFullVersion Forge full version (e.g. 1.14.4-28.2.0).
      * @return True represents all files are ready.
      */
-    default boolean checkExtraFiles(String forgeFullVersion) {
-        JsonObject jo = this.getInstallProfileExtraData(forgeFullVersion);
+    default boolean checkExtraFiles(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        JsonObject jo = this.getInstallProfileExtraData(forgeGroup, forgeArtifact, forgeFullVersion);
         if (jo != null) {
             Map<String, Path> libsMap = new HashMap<>();
             Map<String, String> hashMap = new HashMap<>();
@@ -152,7 +175,7 @@ public interface IFileDetector {
             // Get all "data/<name>/client" elements.
             Pattern artifactPattern = Pattern.compile("^\\[(?<groupId>[^:]*):(?<artifactId>[^:]*):(?<version>[^:@]*)(:(?<classifier>[^@]*))?(@(?<type>[^]]*))?]$");
             for (Map.Entry<String, JsonElement> entry : jo.entrySet()) {
-                String clientStr = getElement(entry.getValue().getAsJsonObject(), "client").getAsString();
+                String clientStr = entry.getValue().getAsJsonObject().get("client").getAsString();
                 if (entry.getKey().endsWith("_SHA")) {
                     Pattern p = Pattern.compile("^'(?<sha1>[A-Za-z0-9]{40})'$");
                     Matcher m = p.matcher(clientStr);
@@ -171,7 +194,7 @@ public interface IFileDetector {
                             .resolve(groupId.replace('.', File.separatorChar))
                             .resolve(artifactId)
                             .resolve(version)
-                            .resolve(artifactId + "-" + version + (classifier.equals("") ? "" : "-") + classifier + "." + type).toAbsolutePath());
+                            .resolve(artifactId + "-" + version + (classifier.isEmpty() ? "" : "-") + classifier + "." + type).toAbsolutePath());
                     }
                 }
             }
@@ -225,14 +248,6 @@ public interface IFileDetector {
         return path != null && Files.isRegularFile(path);
     }
 
-    static JsonElement getElement(JsonObject object, String property) {
-        Optional<Map.Entry<String, JsonElement>> first = object.entrySet().stream().filter(e -> e.getKey().equals(property)).findFirst();
-        if (first.isPresent()) {
-            return first.get().getValue();
-        }
-        return JsonNull.INSTANCE;
-    }
-
     static String getFileSHA1(Path path) {
         try {
             StringBuilder sha1 = new StringBuilder(new BigInteger(1, MessageDigest.getInstance("SHA-1").digest(Files.readAllBytes(path))).toString(16));
diff --git a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/MultiMCFileDetector.java b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/MultiMCFileDetector.java
index cb87d27..a1216f0 100644
--- a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/MultiMCFileDetector.java
+++ b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/detector/MultiMCFileDetector.java
@@ -27,10 +27,16 @@ public class MultiMCFileDetector implements IFileDetector {
     }
 
     @Override
-    public Path getInstallerJar(String forgeFullVersion) {
-        Path path = IFileDetector.super.getInstallerJar(forgeFullVersion);
+    public Path getInstallerJar(String forgeGroup, String forgeArtifact, String forgeFullVersion) {
+        Path path = IFileDetector.super.getInstallerJar(forgeGroup, forgeArtifact, forgeFullVersion);
         if (path == null) {
-            return this.installerJar != null ? this.installerJar : (this.installerJar = this.getLibraryDir().resolve("net").resolve("minecraftforge").resolve("forge").resolve(forgeFullVersion).resolve("forge-" + forgeFullVersion + "-installer.jar").toAbsolutePath());
+            if (this.installerJar == null) {
+                Path installerBase = this.getLibraryDir();
+                for (String dir : forgeGroup.split("\\."))
+                    installerBase = installerBase.resolve(dir);
+                this.installerJar = installerBase.resolve(forgeArtifact).resolve(forgeFullVersion).resolve(forgeArtifact + "-" + forgeFullVersion + "-installer.jar").toAbsolutePath();
+            }
+            return this.installerJar;
         }
         return path;
     }
diff --git a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
index c89d714..9eee574 100644
--- a/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
+++ b/src/main/java/io/github/zekerzhayard/forgewrapper/installer/util/ModuleUtil.java
@@ -1,5 +1,10 @@
 package io.github.zekerzhayard.forgewrapper.installer.util;
 
+import java.io.File;
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
 import java.util.List;
 
 public class ModuleUtil {
@@ -15,6 +20,14 @@ public class ModuleUtil {
         // nothing to do with Java 8
     }
 
+    public static void setupClassPath(Path libraryDir, List<String> paths) throws Throwable {
+        Method addURLMethod = URLClassLoader.class.getDeclaredMethod("addURL", URL.class);
+        addURLMethod.setAccessible(true);
+        for (String path : paths) {
+            addURLMethod.invoke(ClassLoader.getSystemClassLoader(), libraryDir.resolve(path).toUri().toURL());
+        }
+    }
+
     public static Class<?> setupBootstrapLauncher(Class<?> mainClass) {
         // nothing to do with Java 8
         return mainClass;