diff --git a/src/std.py b/src/std.py
--- a/src/std.py
+++ b/src/std.py
@@ -2,7 +2,45 @@ class Number:
 	def __init__(self, x):
 		self.val = x
 
+	def __add__(self, other):
+		return Number(self.val+other.val)
+
+
+class String:
+	def __init__(self, s):
+		self.val = s
+
+	@staticmethod
+	def fromCharCode(x):
+		return String(chr(x.val))
+
+	def __add__(self, other):
+		return String(self.val+other.val)
+
+	def charAt(self, i=None):
+		i = (i or Number(0)).val
+
+		if 0 <= i < len(self.val):
+			return String(self.val[i])
+		else:
+			return String("")
+
+	def substr(self, start=None, length=None):
+		start = (start or Number(0)).val
+		length = length.val if length is not None else len(self.val)
+
+		if length < 0:
+			return String("")
+
+		return String(self.val[start:start+length])
+
+	def slice(self, start=None, end=None):
+		start = (start or Number(0)).val
+		end = end.val if end is not None else None
+		return String(self.val[start:end])
+
 
 lib = {
+	"String": String,
 	"document": {"write": lambda x: print(x.val)}
 }