diff --git a/src/python/loxi/pp.py b/src/python/loxi/pp.py
new file mode 100644
index 0000000..852215d
--- /dev/null
+++ b/src/python/loxi/pp.py
@@ -0,0 +1,248 @@
+"""
+pp - port of Ruby's PP library
+Also based on Lindig, C., & GbR, G. D. (2000). Strictly Pretty.
+
+Example usage:
+>>> import pp.pp as pp
+>>> print pp([[1, 2], [3, 4]], maxwidth=15)
+[
+  [ 1, 2 ],
+  [ 3, 4 ]
+]
+"""
+import unittest
+from contextlib import contextmanager
+
+def pp(obj, maxwidth=79):
+    """
+    Pretty-print the given object.
+    """
+    ctx = PrettyPrinter(maxwidth=maxwidth)
+    ctx.pp(obj)
+    return str(ctx)
+
+
+## Pretty-printers for builtin classes
+
+def pretty_print_list(pp, obj):
+    with pp.group():
+        pp.text('[')
+        with pp.indent(2):
+            for v in obj:
+                if not pp.first(): pp.text(',')
+                pp.breakable()
+                pp.pp(v)
+        pp.breakable()
+        pp.text(']')
+
+def pretty_print_dict(pp, obj):
+    with pp.group():
+        pp.text('{')
+        with pp.indent(2):
+            for (k, v) in sorted(obj.items()):
+                if not pp.first(): pp.text(',')
+                pp.breakable()
+                pp.pp(k)
+                pp.text(': ')
+                pp.pp(v)
+        pp.breakable()
+        pp.text('}')
+
+pretty_printers = {
+    list: pretty_print_list,
+    dict: pretty_print_dict,
+}
+
+
+## Implementation
+
+class PrettyPrinter(object):
+    def __init__(self, maxwidth):
+        self.maxwidth = maxwidth
+        self.cur_indent = 0
+        self.root_group = Group()
+        self.group_stack = [self.root_group]
+
+    def current_group(self):
+        return self.group_stack[-1]
+
+    def text(self, s):
+        self.current_group().append(str(s))
+
+    def breakable(self, sep=' '):
+        self.current_group().append(Breakable(sep, self.cur_indent))
+
+    def first(self):
+        return self.current_group().first()
+
+    @contextmanager
+    def indent(self, n):
+        self.cur_indent += n
+        yield
+        self.cur_indent -= n
+
+    @contextmanager
+    def group(self):
+        self.group_stack.append(Group())
+        yield
+        new_group = self.group_stack.pop()
+        self.current_group().append(new_group)
+
+    def pp(self, obj):
+        if hasattr(obj, "pretty_print"):
+            obj.pretty_print(self)
+        elif type(obj) in pretty_printers:
+            pretty_printers[type(obj)](self, obj)
+        else:
+            self.text(repr(obj))
+
+    def __str__(self):
+        return self.root_group.render(0, self.maxwidth)
+
+class Group(object):
+    __slots__ = ["fragments", "length", "_first"]
+
+    def __init__(self):
+        self.fragments = []
+        self.length = 0
+        self._first = True
+
+    def append(self, x):
+        self.fragments.append(x)
+        self.length += len(x)
+
+    def first(self):
+        if self._first:
+            self._first = False
+            return True
+        return False
+
+    def __len__(self):
+        return self.length
+
+    def render(self, curwidth, maxwidth):
+        dobreak = len(self) > (maxwidth - curwidth)
+
+        a = []
+        for x in self.fragments:
+            if isinstance(x, Breakable):
+                if dobreak:
+                    a.append('\n')
+                    a.append(' ' * x.indent)
+                    curwidth = 0
+                else:
+                    a.append(x.sep)
+            elif isinstance(x, Group):
+                a.append(x.render(curwidth, maxwidth))
+            else:
+                a.append(x)
+            curwidth += len(a[-1])
+        return ''.join(a)
+
+class Breakable(object):
+    __slots__ = ["sep", "indent"]
+
+    def __init__(self, sep, indent):
+        self.sep = sep
+        self.indent = indent
+
+    def __len__(self):
+        return len(self.sep)
+
+
+## Tests
+
+class TestPP(unittest.TestCase):
+    def test_scalars(self):
+        self.assertEquals(pp(1), "1")
+        self.assertEquals(pp("foo"), "'foo'")
+
+    def test_hash(self):
+        expected = """{ 1: 'a', 'b': 2 }"""
+        self.assertEquals(pp(eval(expected)), expected)
+        expected = """\
+{
+  1: 'a',
+  'b': 2
+}"""
+        self.assertEquals(pp(eval(expected), maxwidth=0), expected)
+
+    def test_array(self):
+        expected = """[ 1, 'a', 2 ]"""
+        self.assertEquals(pp(eval(expected)), expected)
+        expected = """\
+[
+  1,
+  'a',
+  2
+]"""
+        self.assertEquals(pp(eval(expected), maxwidth=0), expected)
+
+    def test_nested(self):
+        expected = """[ [ 1, 2 ], [ 3, 4 ] ]"""
+        self.assertEquals(pp(eval(expected)), expected)
+        expected = """\
+[
+  [
+    1,
+    2
+  ],
+  [
+    3,
+    4
+  ]
+]"""
+        self.assertEquals(pp(eval(expected), maxwidth=0), expected)
+
+    def test_breaking(self):
+        expected = """\
+[
+  [ 1, 2 ],
+  'abcdefghijklmnopqrstuvwxyz'
+]"""
+        self.assertEquals(pp(eval(expected), maxwidth=24), expected)
+        expected = """\
+[
+  [ 'abcd', 2 ],
+  [ '0123456789' ],
+  [
+    '0123456789',
+    'abcdefghij'
+  ],
+  [ 'abcdefghijklmnop' ],
+  [
+    'abcdefghijklmnopq'
+  ],
+  { 'k': 'v' },
+  {
+    1: [ 2, [ 3, 4 ] ],
+    'foo': 'abcdefghijklmnop'
+  }
+]"""
+        self.assertEquals(pp(eval(expected), maxwidth=24), expected)
+        expected = """\
+[
+  [ 1, 2 ],
+  [ 3, 4 ]
+]"""
+        self.assertEquals(pp(eval(expected), maxwidth=15), expected)
+
+    # This is an edge case where our simpler algorithm breaks down.
+    @unittest.expectedFailure
+    def test_greedy_breaking(self):
+        expected = """\
+abc def
+ghijklmnopqrstuvwxyz\
+"""
+        pp = PrettyPrinter(maxwidth=8)
+        pp.text("abc")
+        with pp.group():
+            pp.breakable()
+        pp.text("def")
+        with pp.group():
+            pp.breakable()
+        pp.text("ghijklmnopqrstuvwxyz")
+        self.assertEquals(str(pp), expected)
+
+if __name__ == '__main__':
+    unittest.main()