Index: src/Makefile
==================================================================
--- src/Makefile
+++ src/Makefile
@@ -95,10 +95,11 @@
        OFThread.m			\
        OFTimer.m			\
        OFTriple.m			\
        OFURL.m				\
        OFURLHandler.m			\
+       OFUUID.m				\
        OFValue.m			\
        OFXMLAttribute.m			\
        OFXMLCDATA.m			\
        OFXMLCharacters.m		\
        OFXMLComment.m			\

ADDED   src/OFUUID.h
Index: src/OFUUID.h
==================================================================
--- src/OFUUID.h
+++ src/OFUUID.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
+ *
+ * All rights reserved.
+ *
+ * This file is part of ObjFW. It may be distributed under the terms of the
+ * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
+ * the packaging of this file.
+ *
+ * Alternatively, it may be distributed under the terms of the GNU General
+ * Public License, either version 2 or 3, which can be found in the file
+ * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
+ * file.
+ */
+
+#import "OFObject.h"
+
+OF_ASSUME_NONNULL_BEGIN
+
+/**
+ * @class OFUUID OFUUID.h ObjFW/OFUUID.h
+ *
+ * @brief A UUID conforming to RFC 4122.
+ */
+OF_SUBCLASSING_RESTRICTED
+@interface OFUUID: OFObject <OFCopying, OFComparing>
+{
+	unsigned char _bytes[16];
+}
+
+/**
+ * @brief The UUID as a string.
+ */
+@property (readonly, nonatomic) OFString *UUIDString;
+
+/**
+ * @brief Creates a new random UUID as per RFC 4122 version 4.
+ *
+ * @return A new, autoreleased OFUUID
+ */
++ (instancetype)UUID;
+
+/**
+ * @brief Initializes an already allocated OFUUID as a new random UUID as per
+ *	  RFC 4122 version 4.
+ *
+ * @return An initialized OFUUID
+ */
+- (instancetype)init;
+
+/**
+ * @brief Compares the UUID to another UUID.
+ *
+ * @param UUID The UUID to compare to
+ * @return The result of the comparison
+ */
+- (OFComparisonResult)compare: (OFUUID *)UUID;
+@end
+
+OF_ASSUME_NONNULL_END

ADDED   src/OFUUID.m
Index: src/OFUUID.m
==================================================================
--- src/OFUUID.m
+++ src/OFUUID.m
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
+ *
+ * All rights reserved.
+ *
+ * This file is part of ObjFW. It may be distributed under the terms of the
+ * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
+ * the packaging of this file.
+ *
+ * Alternatively, it may be distributed under the terms of the GNU General
+ * Public License, either version 2 or 3, which can be found in the file
+ * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
+ * file.
+ */
+
+#include "config.h"
+
+#import "OFUUID.h"
+#import "OFString.h"
+
+#import "OFInvalidArgumentException.h"
+
+@implementation OFUUID
++ (instancetype)UUID
+{
+	return [[[self alloc] init] autorelease];
+}
+
+- (instancetype)init
+{
+	uint64_t r;
+
+	self = [super init];
+
+	r = OFRandom64();
+	memcpy(_bytes, &r, 8);
+	r = OFRandom64();
+	memcpy(_bytes + 8, &r, 8);
+
+	_bytes[6] &= ~((1 << 7) | (1 << 5) | (1 << 4));
+	_bytes[6] |= (1 << 6);
+	_bytes[8] &= ~(1 << 6);
+	_bytes[8] |= (1 << 7);
+
+	return self;
+}
+
+- (bool)isEqual: (id)object
+{
+	OFUUID *UUID;
+
+	if (![object isKindOfClass: [OFUUID class]])
+		return false;
+
+	UUID = object;
+
+	return (memcmp(_bytes, UUID->_bytes, sizeof(_bytes)) == 0);
+}
+
+- (unsigned long)hash
+{
+	unsigned long hash;
+
+	OFHashInit(&hash);
+
+	for (size_t i = 0; i < sizeof(_bytes); i++)
+		OFHashAdd(&hash, _bytes[i]);
+
+	OFHashFinalize(&hash);
+
+	return hash;
+}
+
+- (id)copy
+{
+	return [self retain];
+}
+
+- (OFComparisonResult)compare: (OFUUID *)UUID
+{
+	int comparison;
+
+	if (![UUID isKindOfClass: [OFUUID class]])
+		@throw [OFInvalidArgumentException exception];
+
+	if ((comparison = memcmp(_bytes, UUID->_bytes, sizeof(_bytes))) == 0)
+		return OFOrderedSame;
+
+	if (comparison > 0)
+		return OFOrderedDescending;
+	else
+		return OFOrderedAscending;
+}
+
+- (OFString *)UUIDString
+{
+	return [OFString stringWithFormat:
+	    @"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-"
+	    @"%02X%02X%02X%02X%02X%02X",
+	    _bytes[0], _bytes[1], _bytes[2], _bytes[3],
+	    _bytes[4], _bytes[5], _bytes[6], _bytes[7],
+	    _bytes[8], _bytes[9], _bytes[10], _bytes[11],
+	    _bytes[12], _bytes[13], _bytes[14], _bytes[15]];
+}
+
+- (OFString *)description
+{
+	return self.UUIDString;
+}
+@end

Index: src/ObjFW.h
==================================================================
--- src/ObjFW.h
+++ src/ObjFW.h
@@ -43,10 +43,11 @@
 #import "OFMethodSignature.h"
 #import "OFInvocation.h"
 
 #import "OFNumber.h"
 #import "OFDate.h"
+#import "OFUUID.h"
 #import "OFURL.h"
 #import "OFURLHandler.h"
 #import "OFColor.h"
 
 #import "OFStream.h"