diff --git a/list_and_trees/double_linked_list.c b/list_and_trees/double_linked_list.c
new file mode 100644
index 0000000..06a5360
--- /dev/null
+++ b/list_and_trees/double_linked_list.c
@@ -0,0 +1,198 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef int Data;
+struct Node {
+	struct Node * next;
+	struct Node * prev;
+	Data data;
+};
+
+
+void list_init(struct Node * list);
+void list_insert(struct Node * list, struct Node * t);
+void list_insert_before(struct Node * list, struct Node * t);
+void list_remove(struct Node * t);
+struct Node * list_push_front(struct Node * list, Data d);
+struct Node * list_push_back(struct Node * list, Data d);
+Data list_pop_front(struct Node * list);
+Data list_pop_back(struct Node * list);
+Data list_delete(struct Node * t);
+void list_print (struct Node * list);
+Data list_sum (struct Node * list);
+int list_is_empty(struct Node * list);
+int list_clear(struct Node * list);
+void list_for_each(struct Node * list, void (*func)(Data d, void * param), void * param);
+void print_it(Data d, void * parameter);
+void sum(Data a, void * s);
+
+void list_init(struct Node * list) {
+	list->next = list;
+	list->prev = list;
+	list->data = 113;
+}
+
+/*void list_print (struct Node * list) {
+	if (list != list->next) {
+		list_for_each(list, print_it, stdout);
+		printf("\n");
+	}
+	else {
+		printf("Empty list\n");
+	}
+}*/
+void list_print (struct Node * list) {
+	struct Node *ptr = list->next;
+	if (ptr == list) {
+		printf("Empty list\n");
+	}
+	else {
+		while (ptr->next != list) {
+			printf("%d ", ptr->data);
+			//printf("%d [%p](prev is %p, next is %p)\n", ptr->data, ptr, ptr->prev, ptr->next);
+			ptr = ptr->next;
+		}
+		printf("%d\n", ptr->data);
+		//printf("%d [%p](prev is %p, next is %p)\n", ptr->data, ptr, ptr->prev, ptr->next);
+	}
+} 
+
+void list_insert(struct Node * list, struct Node * t) {
+	t->next = list->next;
+	t->prev = list;
+	if (t->next != list) {
+		t->next->prev = t;
+	}
+	else {
+		t->next = list;
+		list->prev = t;
+	}
+	list->next = t;
+}
+
+void list_insert_before(struct Node * list, struct Node * t) {
+	t->next = list;
+	t->prev = list->prev;
+	if (t->prev != list) {
+		t->prev->next = t;
+	}
+	else {
+		t->prev = list;
+		list->next = t;
+	}
+	list->prev = t;
+}
+
+void list_remove(struct Node * t) {
+	t->prev->next = t->next;
+	t->next->prev = t->prev;
+}
+
+struct Node * list_push_front(struct Node * list, Data d) {
+	struct Node *ptr = list->next;
+	struct Node *oth = malloc(sizeof(struct Node));
+	oth->data = d;
+	oth->next = ptr;
+	oth->prev = list;
+	list->next = oth;
+	ptr->prev = oth;
+	return list;
+}
+
+struct Node * list_push_back(struct Node * list, Data d) {
+	struct Node *ptr = list->prev;
+	struct Node *oth = malloc(sizeof(struct Node));
+	oth->data = d;
+	oth->next = list;
+	oth->prev = ptr;
+	list->prev = oth;
+	ptr->next = oth;
+	return list;
+}
+
+int list_is_empty(struct Node * list) {
+	if (list == list->next) {
+		return 1;
+	}
+	return 0;
+}
+
+int list_clear(struct Node * list) {
+	struct Node *ptr = list->next;
+	
+	struct Node *next;
+	while (ptr->next != list) {
+		next = ptr->next;
+		free(ptr);
+		ptr = next;
+	}
+	list->next = list;
+	list->prev = list;
+	return 0;
+}
+
+Data list_pop_front(struct Node * list) {
+	struct Node *ptr = list->next;
+	Data val = ptr->data;
+	list->next = ptr->next;
+	ptr->next->prev = list;
+	free(ptr);
+
+	return val;
+}
+
+Data list_pop_back(struct Node * list) {
+	struct Node *ptr = list->prev;
+	Data val = ptr->data;
+	list->prev = ptr->prev;
+	ptr->prev->next = list;
+	free(ptr);
+
+	return val;
+}
+
+Data list_delete(struct Node * t) {
+	t->prev->next = t->next;
+	t->next->prev = t->prev;
+	Data val = t->data;
+	free(t);
+	return val;
+}
+
+void list_for_each(struct Node * list, void (*func)(Data d, void * param), void * param) {
+	struct Node *ptr = list->next;
+	while (ptr->next != list) {
+		func(ptr->data, param);
+		ptr = ptr->next;
+	}
+}
+
+void sum(Data a, void * s) {
+	*(Data *)s += a;
+}
+
+void print_it(Data d, void * param) {
+	FILE * fd = param;
+	fprintf(fd, "%d ", d);
+}
+
+Data list_sum (struct Node * list) {
+	int s = 0;
+	list_for_each(list, sum, &s);
+	return s;
+}
+
+int main() {
+struct Node x[10];
+	struct Node * a = malloc(sizeof(struct Node));
+	struct Node * b = malloc(sizeof(struct Node));
+	int i;
+	list_init(a);
+	list_init(b);
+	
+	for(i=0; i<10; i++) {
+		x[i].data = i;
+		list_insert(a, &x[i]);
+	}
+	list_print(a);
+}