diff --git a/src/thread.cpp b/src/thread.cpp
new file mode 100644
--- /dev/null
+++ b/src/thread.cpp
@@ -0,0 +1,157 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "thread.h"
+#include <stdlib.h>
+
+#if defined(__AMIGA__) || defined(__MORPHOS__) || defined(NO_THREADS)
+OTTDThread *OTTDCreateThread(OTTDThreadFunc function, void *arg) { return NULL; }
+void *OTTDJoinThread(OTTDThread *t) { return NULL; }
+void OTTDExitThread(void) { NOT_REACHED(); };
+
+#elif defined(__OS2__)
+
+#define INCL_DOS
+#include <os2.h>
+#include <process.h>
+
+struct OTTDThread {
+	TID thread;
+	OTTDThreadFunc func;
+	void* arg;
+	void* ret;
+};
+
+static void Proxy(void* arg)
+{
+	OTTDThread* t = arg;
+	t->ret = t->func(t->arg);
+}
+
+OTTDThread* OTTDCreateThread(OTTDThreadFunc function, void* arg)
+{
+	OTTDThread* t = malloc(sizeof(*t));
+
+	if (t == NULL) return NULL;
+
+	t->func = function;
+	t->arg  = arg;
+	t->thread = _beginthread(Proxy, NULL, 32768, t);
+	if (t->thread != -1) {
+		return t;
+	} else {
+		free(t);
+		return NULL;
+	}
+}
+
+void* OTTDJoinThread(OTTDThread* t)
+{
+	void* ret;
+
+	if (t == NULL) return NULL;
+
+	DosWaitThread(&t->thread, DCWW_WAIT);
+	ret = t->ret;
+	free(t);
+	return ret;
+}
+
+void OTTDExitThread(void)
+{
+	_endthread();
+}
+
+#elif defined(UNIX)
+
+#include <pthread.h>
+
+struct OTTDThread {
+	pthread_t thread;
+};
+
+OTTDThread* OTTDCreateThread(OTTDThreadFunc function, void* arg)
+{
+	OTTDThread* t = malloc(sizeof(*t));
+
+	if (t == NULL) return NULL;
+
+	if (pthread_create(&t->thread, NULL, function, arg) == 0) {
+		return t;
+	} else {
+		free(t);
+		return NULL;
+	}
+}
+
+void* OTTDJoinThread(OTTDThread* t)
+{
+	void* ret;
+
+	if (t == NULL) return NULL;
+
+	pthread_join(t->thread, &ret);
+	free(t);
+	return ret;
+}
+
+void OTTDExitThread(void)
+{
+	pthread_exit(NULL);
+}
+
+#elif defined(WIN32)
+
+#include <windows.h>
+
+struct OTTDThread {
+	HANDLE thread;
+	OTTDThreadFunc func;
+	void* arg;
+	void* ret;
+};
+
+static DWORD WINAPI Proxy(LPVOID arg)
+{
+	OTTDThread* t = arg;
+	t->ret = t->func(t->arg);
+	return 0;
+}
+
+OTTDThread* OTTDCreateThread(OTTDThreadFunc function, void* arg)
+{
+	OTTDThread* t = malloc(sizeof(*t));
+	DWORD dwThreadId;
+
+	if (t == NULL) return NULL;
+
+	t->func = function;
+	t->arg  = arg;
+	t->thread = CreateThread(NULL, 0, Proxy, t, 0, &dwThreadId);
+
+	if (t->thread != NULL) {
+		return t;
+	} else {
+		free(t);
+		return NULL;
+	}
+}
+
+void* OTTDJoinThread(OTTDThread* t)
+{
+	void* ret;
+
+	if (t == NULL) return NULL;
+
+	WaitForSingleObject(t->thread, INFINITE);
+	CloseHandle(t->thread);
+	ret = t->ret;
+	free(t);
+	return ret;
+}
+
+void OTTDExitThread(void)
+{
+	ExitThread(0);
+}
+#endif