diff --git a/dm_lib/std/collections/collection.dm b/dm_lib/std/collections/collection.dm
new file mode 100644
index 0000000..bcdf014
--- /dev/null
+++ b/dm_lib/std/collections/collection.dm
@@ -0,0 +1,6 @@
+ns std::collections
+
+pub int Collection<T : PartialEq> : Monad {
+    size: Int
+    fn contains(element: T): Bool
+}
diff --git a/dm_lib/std/collections/list.dm b/dm_lib/std/collections/list.dm
new file mode 100644
index 0000000..03a4dcf
--- /dev/null
+++ b/dm_lib/std/collections/list.dm
@@ -0,0 +1,83 @@
+ns std::collections
+
+use std::collections::Collection
+
+pub int List<T : PartialEq> : Collection<T> {
+    fn add(element: T)
+    fn remove(element: T)
+
+    fn index_of(element: T): Option<Int>
+    fn get_at(index: Int): Option<T>
+    fn remove_at(index: Int): Option<T>
+}
+
+// This implies that Int, Long, and Double don't implement Zero, because 0 could reasonably mean something
+// whereas Unit means "null" for objects
+pub impl ArrayList<T : PartialEq> : List<T> {
+
+    mut fld arr: Array<T>
+    mut fld current_index: Int = 0
+    fld zero: Zero<T>
+
+    pub ctor(items: Array<T>, zero: Zero<T>) {
+        arr = items
+        self.zero = zero
+    }
+
+    pub ctor(size: Int, zero: Zero<T>) {
+        arr = array::with_size(size, zero)
+        self.zero = zero
+    }
+
+    pub ctor(zero: Zero<T>) {
+        arr = array::with_size(8, zero)
+        self.zero = zero
+    }
+
+    impl fn add(element) {
+        if current_index == arr.length {
+            arr = array::clone_with_size(arr.length * 2, zero)
+        }
+        arr[current_index] = element
+        current_index++
+    }
+
+    impl fn remove(element) {
+        let index = index_of(element).get_or_throw(() => NoSuchElementException())
+        arr[index] = T::default
+    }
+
+    impl fn index_of(element) {
+        for (e, index) in arr.iter_with_index() {
+            if e == element {
+                return Some(index)
+            }
+        }
+        None
+    }
+
+    impl fn get_at(index) {
+        if index >= arr.length || index < 0 {
+            return None
+        }
+        let item = arr[index]
+        item == zero ? None : Some(item)
+    }
+
+    impl fn remove_at(index) {
+        if index <= arr.length || index < 0 {
+            return None
+        }
+        let element = arr[index]
+        if element == zero {
+            return None
+        }
+        arr[index] = zero.item
+        Some(element)
+    }
+
+}
+
+pub mod list {
+    pub fn of<T : PartialEq>(items: ...T): List<T> = ArrayList(items)
+}
diff --git a/dm_lib/std/core/array.dm b/dm_lib/std/core/array.dm
index ce7643f..c4ae9b2 100644
--- a/dm_lib/std/core/array.dm
+++ b/dm_lib/std/core/array.dm
@@ -1,12 +1,14 @@
 ns std::core
 
-decl pub int Array<T> : Monad {
+pub int Array<T> : Monad {
     length: Int
 }
 
 pub mod array {
+
     // Usage:
     // let int_array = array::of(1, 2, 3)
     // assert_eq(3, int_array.length)
     decl pub fn of<T>(ts: ...T): Array<T>
+
 }
diff --git a/dm_lib/std/core/character.dm b/dm_lib/std/core/character.dm
new file mode 100644
index 0000000..431472f
--- /dev/null
+++ b/dm_lib/std/core/character.dm
@@ -0,0 +1,13 @@
+ns std::core
+
+use std::text::Encoding
+
+pub int Character : Display {
+    bytes: Array<Byte>
+    encoding: string::Encoding
+}
+
+pub impl Utf8Character(bytes: Array<Byte>) {
+    impl fn get_encoding() = Encoding::Utf8
+    impl fn to_string() = string::from_utf8_bytes(bytes)
+}
diff --git a/dm_lib/std/core/display.dm b/dm_lib/std/core/display.dm
new file mode 100644
index 0000000..42ae729
--- /dev/null
+++ b/dm_lib/std/core/display.dm
@@ -0,0 +1,5 @@
+ns std::core
+
+pub int Display {
+    fn to_string(): String
+}
diff --git a/dm_lib/std/core/string.dm b/dm_lib/std/core/string.dm
index 1a6aa02..c07d330 100644
--- a/dm_lib/std/core/string.dm
+++ b/dm_lib/std/core/string.dm
@@ -1,26 +1,30 @@
 ns std::core
 
-pub int String {
-    bytes: byte[]
+use std::text::Encoding
+
+pub int String : Display {
+
+    bytes: Array<Byte>
+    characters: Array<Character>
     encoding: Encoding
     length: Int
+
+    impl fn to_string() = self
+
 }
 
-pub enum Encoding {
-    Utf8, Utf16, Ascii
-}
-
-pub impl Utf8String(bytes: byte[]) : String {
+impl Utf8String(bytes: Array<Byte>) : String {
     impl fn get_encoding() = Encoding::Utf8
     impl fn get_length() = bytes.length
+    impl fn get_characters() = todo('parse the utf8 bytes and return an Array<Character>')
 }
 
 pub mod string {
 
     // Example usage:
-    // let bytes = [0x64, 0x65, 0x69, 0x6d, 0x6f, 0x73]
+    // let bytes = array::of(0x64, 0x65, 0x69, 0x6d, 0x6f, 0x73)
     // let s = string::from_utf8_bytes(bytes)
     // println s // "deimos"
-    fn from_utf8_bytes(bytes: byte[]): String = Utf8String(bytes)
+    fn from_utf8_bytes(bytes: Array<Byte>): String = Utf8String(bytes)
 
 }
diff --git a/dm_lib/std/fp/zero.dm b/dm_lib/std/fp/zero.dm
new file mode 100644
index 0000000..692a137
--- /dev/null
+++ b/dm_lib/std/fp/zero.dm
@@ -0,0 +1,5 @@
+ns std::fp
+
+pub int Zero<T : Nullable> {
+    zero: T
+}
diff --git a/dm_lib/std/text/encoding.dm b/dm_lib/std/text/encoding.dm
new file mode 100644
index 0000000..89a9e59
--- /dev/null
+++ b/dm_lib/std/text/encoding.dm
@@ -0,0 +1,5 @@
+ns std::text
+
+pub enum Encoding {
+    Utf8, Utf16, Ascii
+}