diff --git a/include/system.hpp b/include/system.hpp
index 036d16db..12c30002 100644
--- a/include/system.hpp
+++ b/include/system.hpp
@@ -2,11 +2,16 @@
 #include <list>
 
 #include <common.hpp>
+#include <experimental/filesystem>
 
 
 namespace rack {
 
 
+// In C++17, this will be `std::filesystem`
+namespace filesystem = std::experimental::filesystem;
+
+
 /** Cross-platform functions for operating systems routines
 */
 namespace system {
@@ -64,11 +69,11 @@ The launched process will continue running if the current process is closed.
 */
 void runProcessDetached(const std::string& path);
 std::string getOperatingSystemInfo();
-/** Unzips a ZIP file to a folder.
-The folder must exist.
-Returns 0 if successful.
+/** Extracts an archive into a folder.
+Currently supports the "ustar zstd" format (.tar.zstd)
 */
-int unzipToFolder(const std::string& zipPath, const std::string& dir);
+void unarchiveToFolder(const filesystem::path& archivePath, const filesystem::path& folderPath);
+void archiveFolder(const filesystem::path& archivePath, const filesystem::path& folderPath);
 
 
 } // namespace system
diff --git a/src/patch.cpp b/src/patch.cpp
index 6a0183e2..6eb7192a 100644
--- a/src/patch.cpp
+++ b/src/patch.cpp
@@ -55,7 +55,7 @@ void PatchManager::save(std::string path) {
 	INFO("Saving patch %s", path.c_str());
 	saveAutosave();
 
-	// TODO Archive autosave folder
+	system::archiveFolder(path, asset::autosavePath);
 }
 
 void PatchManager::saveDialog() {
@@ -141,8 +141,11 @@ void PatchManager::saveAutosave() {
 bool PatchManager::load(std::string path) {
 	INFO("Loading patch %s", path.c_str());
 
-	// TODO Extract archive to autosave
+	filesystem::remove_all(asset::autosavePath);
+	filesystem::create_directories(asset::autosavePath);
+	system::unarchiveToFolder(path, asset::autosavePath);
 
+	loadAutosave();
 	return true;
 }
 
@@ -174,7 +177,7 @@ void PatchManager::loadAutosave() {
 	FILE* file = std::fopen(patchPath.c_str(), "r");
 	if (!file) {
 		// Exit silently
-		// TODO Load autosave
+		// TODO Load template
 		return;
 	}
 	DEFER({
diff --git a/src/plugin.cpp b/src/plugin.cpp
index 9147f6e4..b07acd37 100644
--- a/src/plugin.cpp
+++ b/src/plugin.cpp
@@ -197,8 +197,11 @@ static void extractPackages(std::string path) {
 			continue;
 		INFO("Extracting package %s", packagePath.c_str());
 		// Extract package
-		if (system::unzipToFolder(packagePath, path)) {
-			WARN("Package %s failed to extract", packagePath.c_str());
+		try {
+			system::unarchiveToFolder(packagePath, path);
+		}
+		catch (Exception& e) {
+			WARN("Package %s failed to extract: %s", packagePath.c_str(), e.what());
 			message += string::f("Could not extract package %s\n", packagePath.c_str());
 			continue;
 		}
@@ -240,7 +243,7 @@ void init() {
 	std::string fundamentalDir = asset::pluginsPath + "/Fundamental";
 	if (!settings::devMode && !getPlugin("Fundamental") && system::isFile(fundamentalSrc)) {
 		INFO("Extracting bundled Fundamental package");
-		system::unzipToFolder(fundamentalSrc.c_str(), asset::pluginsPath.c_str());
+		system::unarchiveToFolder(fundamentalSrc.c_str(), asset::pluginsPath.c_str());
 		loadPlugin(fundamentalDir);
 	}
 
diff --git a/src/system.cpp b/src/system.cpp
index 93c7afdf..88b04655 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -28,6 +28,8 @@
 
 #define ZIP_STATIC
 #include <zip.h>
+#include <archive.h>
+#include <archive_entry.h>
 
 #include <system.hpp>
 #include <string.hpp>
@@ -428,5 +430,154 @@ int unzipToFolder(const std::string& zipPath, const std::string& dir) {
 }
 
 
+void unarchiveToFolder(const filesystem::path& archivePath, const filesystem::path& folderPath) {
+	// Based on minitar.c extract() in libarchive examples
+	int r;
+
+	// Open archive for reading
+	struct archive* a = archive_read_new();
+	DEFER({archive_read_free(a);});
+	archive_read_support_filter_zstd(a);
+	// archive_read_support_filter_all(a);
+	archive_read_support_format_tar(a);
+	// archive_read_support_format_all(a);
+	// TODO Fix unicode filenames on Windows?
+	r = archive_read_open_filename(a, archivePath.c_str(), 1 << 14);
+	if (r != ARCHIVE_OK)
+		throw Exception(string::f("unzipToFolder() could not open archive %s: %s", archivePath.c_str(), archive_error_string(a)));
+	DEFER({archive_read_close(a);});
+
+	// Open folder for writing
+	struct archive* disk = archive_write_disk_new();
+	DEFER({archive_write_free(disk);});
+	int flags = ARCHIVE_EXTRACT_TIME;
+	archive_write_disk_set_options(disk, flags);
+	// archive_write_disk_set_standard_lookup(disk);
+	DEFER({archive_write_close(disk);});
+
+	// Iterate archive
+	for (;;) {
+		// Get next entry
+		struct archive_entry* entry;
+		r = archive_read_next_header(a, &entry);
+		if (r == ARCHIVE_EOF)
+			break;
+		if (r < ARCHIVE_OK)
+			throw Exception(string::f("unzipToFolder() could not read entry from archive: %s", archive_error_string(a)));
+
+		// Set pathname relative to folderPath
+		filesystem::path entryPath = archive_entry_pathname(entry);
+		if (!entryPath.is_relative())
+			throw Exception(string::f("unzipToFolder() does not support absolute paths: %s", entryPath.c_str()));
+		entryPath = filesystem::absolute(entryPath, folderPath);
+		archive_entry_set_pathname(entry, entryPath.c_str());
+
+		// Write entry to disk
+		r = archive_write_header(disk, entry);
+		if (r < ARCHIVE_OK)
+			throw Exception(string::f("unzipToFolder() could not write file to folder: %s", archive_error_string(disk)));
+
+		// Copy data to file
+		for (;;) {
+			const void* buf;
+			size_t size;
+			int64_t offset;
+			// Read data from archive
+			r = archive_read_data_block(a, &buf, &size, &offset);
+			if (r == ARCHIVE_EOF)
+				break;
+			if (r < ARCHIVE_OK)
+				throw Exception(string::f("unzipToFolder() could not read data from archive", archive_error_string(a)));
+
+			// Write data to file
+			r = archive_write_data_block(disk, buf, size, offset);
+			if (r < ARCHIVE_OK)
+				throw Exception(string::f("unzipToFolder() could not write data to file", archive_error_string(disk)));
+		}
+
+		// Close file
+		r = archive_write_finish_entry(disk);
+		if (r < ARCHIVE_OK)
+			throw Exception(string::f("unzipToFolder() could not close file", archive_error_string(disk)));
+	}
+}
+
+
+/** Behaves like `std::filesystem::relative()`.
+Limitation: `p` must be a descendant of `base`. Doesn't support adding `../` to the return path.
+*/
+static filesystem::path getRelativePath(filesystem::path p, filesystem::path base = filesystem::current_path()) {
+	p = filesystem::absolute(p);
+	base = filesystem::absolute(base);
+	std::string pStr = p;
+	std::string baseStr = base;
+	if (pStr.size() < baseStr.size())
+		throw Exception("getRelativePath() error: path is shorter than base");
+	if (!std::equal(baseStr.begin(), baseStr.end(), pStr.begin()))
+		throw Exception("getRelativePath() error: path does not begin with base");
+
+	// If p == base, this correctly returns "."
+	return "." + std::string(pStr.begin() + baseStr.size(), pStr.end());
+}
+
+
+void archiveFolder(const filesystem::path& archivePath, const filesystem::path& folderPath){
+	// Based on minitar.c create() in libarchive examples
+	int r;
+
+	// Open archive for writing
+	struct archive* a = archive_write_new();
+	DEFER({archive_write_free(a);});
+	archive_write_set_format_ustar(a);
+	archive_write_add_filter_zstd(a);
+	r = archive_write_open_filename(a, archivePath.c_str());
+	if (r != ARCHIVE_OK)
+		throw Exception(string::f("archiveFolder() could not open archive %s for writing: %s", archivePath.c_str(), archive_error_string(a)));
+	DEFER({archive_write_close(a);});
+
+	// Open folder for reading
+	struct archive* disk = archive_read_disk_new();
+	DEFER({archive_read_free(disk);});
+	r = archive_read_disk_open(disk, folderPath.c_str());
+	if (r != ARCHIVE_OK)
+		throw Exception(string::f("archiveFolder() could not open folder %s for reading: %s", folderPath.c_str(), archive_error_string(a)));
+	DEFER({archive_read_close(a);});
+
+	// Iterate folder
+	for (;;) {
+		struct archive_entry* entry = archive_entry_new();
+		DEFER({archive_entry_free(entry);});
+
+		r = archive_read_next_header2(disk, entry);
+		if (r == ARCHIVE_EOF)
+			break;
+		if (r != ARCHIVE_OK)
+			throw Exception(string::f("archiveFolder() could not get next entry from archive: %s", archive_error_string(disk)));
+
+		// Recurse dirs
+		archive_read_disk_descend(disk);
+
+		// Convert absolute path to relative path
+		filesystem::path entryPath = archive_entry_pathname(entry);
+		entryPath = getRelativePath(entryPath, folderPath);
+		archive_entry_set_pathname(entry, entryPath.c_str());
+
+		// Write file to archive
+		r = archive_write_header(a, entry);
+		if (r != ARCHIVE_OK)
+			throw Exception("archiveFolder() could not write entry to archive");
+
+		// Manually copy data
+		FILE* f = std::fopen(archive_entry_sourcepath(entry), "rb");
+		DEFER({std::fclose(f);});
+		static char buf[1 << 14];
+		ssize_t len;
+		while ((len = std::fread(buf, 1, sizeof(buf), f)) > 0) {
+			archive_write_data(a, buf, len);
+		}
+	}
+}
+
+
 } // namespace system
 } // namespace rack