diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..bee8a64
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+__pycache__
diff --git a/__init__.py b/__init__.py
index b34ae90..11c76bd 100644
--- a/__init__.py
+++ b/__init__.py
@@ -3,154 +3,8 @@
 import binascii
 import sys
 import struct
+from . import ip
 
-stdch = (
-    '␀·········␊··␍··'
-    '················'
-    ' !"#$%&\'()*+,-./'
-    '0123456789:;<=>?'
-    '@ABCDEFGHIJKLMNO'
-    'PQRSTUVWXYZ[\]^_'
-    '`abcdefghijklmno'
-    'pqrstuvwxyz{|}~·'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-)
-
-decch = (
-    '␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏'
-    '␐␑␒␓␔␕␖␗␘␙␚·····'
-    '␠!"#$%&\'()*+,-./'
-    '0123456789:;<=>?'
-    '@ABCDEFGHIJKLMNO'
-    'PQRSTUVWXYZ[\]^_'
-    '`abcdefghijklmno'
-    'pqrstuvwxyz{|}~␡'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-    '················'
-)
-
-cgach = (
-    '□☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
-	'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
-	' !"#$%&\'()*+,-./'
-	'0123456789:;<=>?'
-	'@ABCDEFGHIJKLMNO'
-	'PQRSTUVWXYZ[\]^_'
-	'`abcdefghijklmno'
-	'pqrstuvwxyz{|}~⌂'
-	'ÇüéâäàåçêëèïîìÄÅ'
-	'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
-	'áíóúñѪº¿⌐¬½¼¡«»'
-	'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
-	'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
-	'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
-	'αßΓπΣσµτΦΘΩδ∞φε∩'
-	'≡±≥≤⌠⌡÷≈°∙·√ⁿ²■¤'
-)
-
-fluffych = (
-    '·☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
-	'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
-	' !"#$%&\'()*+,-./'
-	'0123456789:;<=>?'
-	'@ABCDEFGHIJKLMNO'
-	'PQRSTUVWXYZ[\]^_'
-	'`abcdefghijklmno'
-	'pqrstuvwxyz{|}~⌂'
-	'ÇüéâäàåçêëèïîìÄÅ'
-	'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
-	'áíóúñѪº¿⌐¬½¼¡«»'
-	'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
-	'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
-	'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
-	'αßΓπΣσµτΦΘΩδ∞φε∩'
-	'≡±≥≤⌠⌡÷≈°∀∃√ⁿ²■¤'
-)
-
-
-def unpack(fmt, buf):
-    """Unpack buf based on fmt, return the remainder."""
-
-    size = struct.calcsize(fmt)
-    vals = struct.unpack(fmt, bytes(buf[:size]))
-    return vals + (buf[size:],)
-
-
-class HexDumper:
-    def __init__(self, output, charset=fluffych):
-        self.offset = 0
-        self.last = None
-        self.elided = False
-        self.hexes = []
-        self.chars = []
-        self.charset = charset
-        self.output = output
-
-    def _spit(self):
-        if self.chars == self.last:
-            if not self.elided:
-                self.output.write('*\n')
-                self.elided = True
-            self.hexes = []
-            self.chars = []
-            return
-        self.last = self.chars[:]
-        self.elided = False
-
-        pad = 16 - len(self.chars)
-        self.hexes += ['  '] * pad
-
-        self.output.write('{:08x}  '.format(self.offset - len(self.chars)))
-        self.output.write(' '.join(self.hexes[:8]))
-        self.output.write('  ')
-        self.output.write(' '.join(self.hexes[8:]))
-        self.output.write('  ')
-        self.output.write(''.join(self.chars))
-        self.output.write('\n')
-
-        self.hexes = []
-        self.chars = []
-
-    def add(self, b):
-        if self.offset and self.offset % 16 == 0:
-            self._spit()
-
-        if b is None:
-            h = '⬜'
-            c = '�'
-        else:
-            h = '{:02x}'.format(b)
-            c = self.charset[b]
-        self.chars.append(c)
-        self.hexes.append(h)
-
-        self.offset += 1
-
-    def done(self):
-        self._spit()
-        self.output.write('{:08x}\n'.format(self.offset))
-
-
-def hexdump(buf, f=sys.stdout, charset=fluffych):
-    "Print a hex dump of buf"
-
-    h = HexDumper(output=f, charset=charset)
-    for b in buf:
-        h.add(b)
-    h.done()
 
 
 def cstring(buf):
@@ -160,10 +14,6 @@ def cstring(buf):
     return buf[:i]
 
 
-def md5sum(txt):
-    return md5.new(txt).hexdigest()
-
-
 def assert_equal(a, b):
     assert a == b, ('%r != %r' % (a, b))
 
@@ -218,7 +68,7 @@ class BitVector:
         """Iterate from LSB to MSB"""
 
         v = self._val
-        for i in xrange(self._len):
+        for _ in range(self._len):
             yield int(v & 1)
             v >>= 1
 
@@ -282,7 +132,7 @@ import string
 b64alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
 
 def from_b64(s, alphabet, codec='base64'):
-    tr = string.maketrans(alphabet, b64alpha)
+    tr = alphabet.maketrans(b64alpha)
     t = s.translate(tr)
     return t.decode(codec)
 
@@ -330,3 +180,15 @@ def _registry(encoding):
                 Esab64StreamReader, Esab64StreamWriter)
 
 codecs.register(_registry)
+
+def main(session):
+    s = None
+    reseq = ip.Dispatch(*sys.argv[1:])
+    for _, d in reseq:
+        srv, first, chunk = d
+        if not s:
+            s = session(first)
+        s.handle(srv, first, chunk, reseq.last)
+
+Session = ip.Session
+Packet = ip.Packet
diff --git a/dumbdecode.py b/dumbdecode.py
index 22caae5..81ce142 100755
--- a/dumbdecode.py
+++ b/dumbdecode.py
@@ -1,20 +1,12 @@
 #! /usr/bin/python3
 
-import sys
-from netarch import ip
-from netarch import *
+import netarch
 
-class DumbPacket(ip.Packet):
-    def parse(self, data):
-        self.payload = data
+class DumbPacket(netarch.Packet):
+	def parse(self, data):
+		self.payload = data
 
-class DumbSession(ip.Session):
-    Packet = DumbPacket
+class DumbSession(netarch.Session):
+	Packet = DumbPacket
 
-s = None
-reseq = ip.Dispatch(*sys.argv[1:])
-for h, d in reseq:
-    srv, first, chunk = d
-    if not s:
-        s = DumbSession(first)
-    s.handle(srv, first, chunk, reseq.last)
+netarch.main(DumbSession)
diff --git a/hexdump.py b/hexdump.py
new file mode 100644
index 0000000..d84e1a1
--- /dev/null
+++ b/hexdump.py
@@ -0,0 +1,140 @@
+import sys
+
+stdch = (
+    '␀·········␊··␍··'
+    '················'
+    ' !"#$%&\'()*+,-./'
+    '0123456789:;<=>?'
+    '@ABCDEFGHIJKLMNO'
+    'PQRSTUVWXYZ[\\]^_'
+    '`abcdefghijklmno'
+    'pqrstuvwxyz{|}~·'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+)
+
+decch = (
+    '␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏'
+    '␐␑␒␓␔␕␖␗␘␙␚·····'
+    '␠!"#$%&\'()*+,-./'
+    '0123456789:;<=>?'
+    '@ABCDEFGHIJKLMNO'
+    'PQRSTUVWXYZ[\\]^_'
+    '`abcdefghijklmno'
+    'pqrstuvwxyz{|}~␡'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+    '················'
+)
+
+cgach = (
+    '□☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
+	'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
+	' !"#$%&\'()*+,-./'
+	'0123456789:;<=>?'
+	'@ABCDEFGHIJKLMNO'
+	'PQRSTUVWXYZ[\\]^_'
+	'`abcdefghijklmno'
+	'pqrstuvwxyz{|}~⌂'
+	'ÇüéâäàåçêëèïîìÄÅ'
+	'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
+	'áíóúñѪº¿⌐¬½¼¡«»'
+	'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
+	'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
+	'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
+	'αßΓπΣσµτΦΘΩδ∞φε∩'
+	'≡±≥≤⌠⌡÷≈°∙·√ⁿ²■¤'
+)
+
+fluffych = (
+    '·☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
+	'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
+	' !"#$%&\'()*+,-./'
+	'0123456789:;<=>?'
+	'@ABCDEFGHIJKLMNO'
+	'PQRSTUVWXYZ[\\]^_'
+	'`abcdefghijklmno'
+	'pqrstuvwxyz{|}~⌂'
+	'ÇüéâäàåçêëèïîìÄÅ'
+	'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
+	'áíóúñѪº¿⌐¬½¼¡«»'
+	'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
+	'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
+	'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
+	'αßΓπΣσµτΦΘΩδ∞φε∩'
+	'≡±≥≤⌠⌡÷≈°∀∃√ⁿ²■¤'
+)
+
+class HexDumper:
+    def __init__(self, output, charset=fluffych):
+        self.offset = 0
+        self.last = None
+        self.elided = False
+        self.hexes = []
+        self.chars = []
+        self.charset = charset
+        self.output = output
+
+    def _spit(self):
+        if self.chars == self.last:
+            if not self.elided:
+                self.output.write('*\n')
+                self.elided = True
+            self.hexes = []
+            self.chars = []
+            return
+        self.last = self.chars[:]
+        self.elided = False
+
+        pad = 16 - len(self.chars)
+        self.hexes += ['  '] * pad
+
+        self.output.write('{:08x}  '.format(self.offset - len(self.chars)))
+        self.output.write(' '.join(self.hexes[:8]))
+        self.output.write('  ')
+        self.output.write(' '.join(self.hexes[8:]))
+        self.output.write('  ')
+        self.output.write(''.join(self.chars))
+        self.output.write('\n')
+
+        self.hexes = []
+        self.chars = []
+
+    def add(self, b):
+        if self.offset and self.offset % 16 == 0:
+            self._spit()
+
+        if b is None:
+            h = '⬜'
+            c = '�'
+        else:
+            h = '{:02x}'.format(b)
+            c = self.charset[b]
+        self.chars.append(c)
+        self.hexes.append(h)
+
+        self.offset += 1
+
+    def done(self):
+        self._spit()
+        self.output.write('{:08x}\n'.format(self.offset))
+
+
+def hexdump(buf, f=sys.stdout, charset=fluffych):
+    "Print a hex dump of buf"
+
+    h = HexDumper(output=f, charset=charset)
+    for b in buf:
+        h.add(b)
+    h.done()
diff --git a/ip.py b/ip.py
index 7b3a8d4..0043aaf 100644
--- a/ip.py
+++ b/ip.py
@@ -13,12 +13,20 @@ try:
     import pcap
 except ImportError:
     warnings.warn("Using slow pure-python pcap library")
-    import netarch.py_pcap as pcap
+    from . import py_pcap as pcap
 import os
 import cgi
 import urllib.parse
-from netarch import unpack, hexdump
-from netarch.trilobytes import TriloBytes
+from .hexdump import hexdump
+from .trilobytes import TriloBytes
+
+def unpack(fmt, buf):
+    """Unpack buf based on fmt, return the remainder."""
+
+    size = struct.calcsize(fmt)
+    vals = struct.unpack(fmt, bytes(buf[:size]))
+    return vals + (buf[size:],)
+
 
 def unpack_nybbles(byte):
     return (byte >> 4, byte & 0x0F)
@@ -65,7 +73,6 @@ class Frame:
              p) = unpack('!HHBBH6si6si', p)
             self.saddr = self.ar_sip
             self.daddr = self.ar_tip
-            self.__repr__ = self.__arp_repr__
         elif self.eth_type == IP:
             # IP
             (self.ihlvers,
@@ -146,18 +153,18 @@ class Frame:
     dst_addr = property(get_dst_addr)
 
     def __repr__(self):
-        return ('<Frame %s %s:%r(%08x) -> %s:%r(%08x) length %d>' %
-                (self.name,
-                 self.src_addr, self.sport, self.seq,
-                 self.dst_addr, self.dport, self.ack,
-                 len(self.payload)))
-
-    def __arp_repr__(self):
-        return '<Frame %s %s(%s) -> %s(%s)>' % (self.name,
-                                                str_of_eth(self.ar_sha),
-                                                self.src_addr,
-                                                str_of_eth(self.ar_tha),
-                                                self.dst_addr)
+        if self.eth_type == ARP:
+            return '<Frame %s %s(%s) -> %s(%s)>' % (self.name,
+                                                    str_of_eth(self.ar_sha),
+                                                    self.src_addr,
+                                                    str_of_eth(self.ar_tha),
+                                                    self.dst_addr)
+        else:
+            return ('<Frame %s %s:%r(%08x) -> %s:%r(%08x) length %d>' %
+                    (self.name,
+                    self.src_addr, self.sport, self.seq,
+                    self.dst_addr, self.dport, self.ack,
+                    len(self.payload)))
 
 class TCP_Recreate:
     closed = True
@@ -360,16 +367,6 @@ class TCP_Resequence:
         return (xdi, first, gs)
 
 
-    def handle(self, pkt):
-        """Stub.
-
-        This function will never be called, it is immediately overridden
-        by __init__.  The current value of self.handle is the state.
-        """
-
-        raise NotImplementedError()
-
-
     def handle_handshake(self, pkt):
         if not self.first:
             self.first = pkt