diff --git a/hgext/graphlog.py b/hgext/graphlog.py
new file mode 100644
--- /dev/null
+++ b/hgext/graphlog.py
@@ -0,0 +1,266 @@
+# ASCII graph log extension for Mercurial
+#
+# Copyright 2007 Joel Rosdahl <joel@rosdahl.net>
+# 
+# This software may be used and distributed according to the terms of
+# the GNU General Public License, incorporated herein by reference.
+
+import sys
+from mercurial.cmdutil import revrange, show_changeset
+from mercurial.i18n import _
+from mercurial.node import nullid, nullrev
+from mercurial.util import Abort
+
+def revision_grapher(repo, start_rev, stop_rev):
+    """incremental revision grapher
+
+    This generator function walks through the revision history from
+    revision start_rev to revision stop_rev (which must be less than
+    or equal to start_rev) and for each revision emits tuples with the
+    following elements:
+
+      - Current revision.
+      - Current node.
+      - Column of the current node in the set of ongoing edges.
+      - Edges; a list of (col, next_col) indicating the edges between
+        the current node and its parents.
+      - Number of columns (ongoing edges) in the current revision.
+      - The difference between the number of columns (ongoing edges)
+        in the next revision and the number of columns (ongoing edges)
+        in the current revision. That is: -1 means one column removed;
+        0 means no columns added or removed; 1 means one column added.
+    """
+
+    assert start_rev >= stop_rev
+    curr_rev = start_rev
+    revs = []
+    while curr_rev >= stop_rev:
+        node = repo.changelog.node(curr_rev)
+
+        # Compute revs and next_revs.
+        if curr_rev not in revs:
+            # New head.
+            revs.append(curr_rev)
+        rev_index = revs.index(curr_rev)
+        next_revs = revs[:]
+
+        # Add parents to next_revs.
+        parents = get_rev_parents(repo, curr_rev)
+        parents_to_add = []
+        for parent in parents:
+            if parent not in next_revs:
+                parents_to_add.append(parent)
+        parents_to_add.sort()
+        next_revs[rev_index:rev_index + 1] = parents_to_add
+
+        edges = []
+        for parent in parents:
+            edges.append((rev_index, next_revs.index(parent)))
+
+        n_columns_diff = len(next_revs) - len(revs)
+        yield (curr_rev, node, rev_index, edges, len(revs), n_columns_diff)
+
+        revs = next_revs
+        curr_rev -= 1
+
+def get_rev_parents(repo, rev):
+    return [x for x in repo.changelog.parentrevs(rev) if x != nullrev]
+
+def fix_long_right_edges(edges):
+    for (i, (start, end)) in enumerate(edges):
+        if end > start:
+            edges[i] = (start, end + 1)
+
+def draw_edges(edges, nodeline, interline):
+    for (start, end) in edges:
+        if start == end + 1:
+            interline[2 * end + 1] = "/"
+        elif start == end - 1:
+            interline[2 * start + 1] = "\\"
+        elif start == end:
+            interline[2 * start] = "|"
+        else:
+            nodeline[2 * end] = "+"
+            if start > end:
+                (start, end) = (end,start)
+            for i in range(2 * start + 1, 2 * end):
+                if nodeline[i] != "+":
+                    nodeline[i] = "-"
+
+def format_line(line, level, logstr):
+    text = "%-*s %s" % (2 * level, "".join(line), logstr)
+    return "%s\n" % text.rstrip()
+
+def get_nodeline_edges_tail(
+        node_index, p_node_index, n_columns, n_columns_diff, p_diff, fix_tail):
+    if fix_tail and n_columns_diff == p_diff and n_columns_diff != 0:
+        # Still going in the same non-vertical direction.
+        if n_columns_diff == -1:
+            start = max(node_index + 1, p_node_index)
+            tail = ["|", " "] * (start - node_index - 1)
+            tail.extend(["/", " "] * (n_columns - start))
+            return tail
+        else:
+            return ["\\", " "] * (n_columns - node_index - 1)
+    else:
+        return ["|", " "] * (n_columns - node_index - 1)
+
+def get_padding_line(ni, n_columns, edges):
+    line = []
+    line.extend(["|", " "] * ni)
+    if (ni, ni - 1) in edges or (ni, ni) in edges:
+        # (ni, ni - 1)      (ni, ni)
+        # | | | |           | | | |
+        # +---o |           | o---+
+        # | | c |           | c | |
+        # | |/ /            | |/ /
+        # | | |             | | |
+        c = "|"
+    else:
+        c = " "
+    line.extend([c, " "])
+    line.extend(["|", " "] * (n_columns - ni - 1))
+    return line
+
+def get_limit(limit_opt):
+    if limit_opt:
+        try:
+            limit = int(limit_opt)
+        except ValueError:
+            raise Abort(_("limit must be a positive integer"))
+        if limit <= 0:
+            raise Abort(_("limit must be positive"))
+    else:
+        limit = sys.maxint
+    return limit
+
+def get_revs(repo, rev_opt):
+    if rev_opt:
+        revs = revrange(repo, rev_opt)
+        return (max(revs), min(revs))
+    else:
+        return (repo.changelog.count() - 1, 0)
+
+def graphlog(ui, repo, *args, **opts):
+    """show revision history alongside an ASCII revision graph
+
+    Print a revision history alongside a revision graph drawn with
+    ASCII characters.
+
+    Nodes printed as an @ character are parents of the working
+    directory.
+    """
+
+    limit = get_limit(opts["limit"])
+    (start_rev, stop_rev) = get_revs(repo, opts["rev"])
+    stop_rev = max(stop_rev, start_rev - limit + 1)
+    if start_rev == nullrev:
+        return
+    cs_printer = show_changeset(ui, repo, opts)
+    grapher = revision_grapher(repo, start_rev, stop_rev)
+    repo_parents = repo.dirstate.parents()
+    prev_n_columns_diff = 0
+    prev_node_index = 0
+
+    for (rev, node, node_index, edges, n_columns, n_columns_diff) in grapher:
+        # log_strings is the list of all log strings to draw alongside
+        # the graph.
+        ui.pushbuffer()
+        cs_printer.show(rev, node)
+        log_strings = ui.popbuffer().split("\n")[:-1]
+
+        if n_columns_diff == -1:
+            # Transform
+            #
+            #     | | |        | | |
+            #     o | |  into  o---+
+            #     |X /         |/ /
+            #     | |          | |
+            fix_long_right_edges(edges)
+
+        # add_padding_line says whether to rewrite
+        #
+        #     | | | |        | | | |
+        #     | o---+  into  | o---+
+        #     |  / /         |   | |  # <--- padding line
+        #     o | |          |  / /
+        #                    o | |
+        add_padding_line = \
+            len(log_strings) > 2 and \
+            n_columns_diff == -1 and \
+            [x for (x, y) in edges if x + 1 < y]
+
+        # fix_nodeline_tail says whether to rewrite
+        #
+        #     | | o | |        | | o | |
+        #     | | |/ /         | | |/ /
+        #     | o | |    into  | o / /   # <--- fixed nodeline tail
+        #     | |/ /           | |/ /
+        #     o | |            o | |
+        fix_nodeline_tail = len(log_strings) <= 2 and not add_padding_line
+
+        # nodeline is the line containing the node character (@ or o).
+        nodeline = ["|", " "] * node_index
+        if node in repo_parents:
+            node_ch = "@"
+        else:
+            node_ch = "o"
+        nodeline.extend([node_ch, " "])
+
+        nodeline.extend(
+            get_nodeline_edges_tail(
+                node_index, prev_node_index, n_columns, n_columns_diff,
+                prev_n_columns_diff, fix_nodeline_tail))
+
+        # shift_interline is the line containing the non-vertical
+        # edges between this entry and the next.
+        shift_interline = ["|", " "] * node_index
+        if n_columns_diff == -1:
+            n_spaces = 1
+            edge_ch = "/"
+        elif n_columns_diff == 0:
+            n_spaces = 2
+            edge_ch = "|"
+        else:
+            n_spaces = 3
+            edge_ch = "\\"
+        shift_interline.extend(n_spaces * [" "])
+        shift_interline.extend([edge_ch, " "] * (n_columns - node_index - 1))
+
+        # Draw edges from the current node to its parents.
+        draw_edges(edges, nodeline, shift_interline)
+
+        # lines is the list of all graph lines to print.
+        lines = [nodeline]
+        if add_padding_line:
+            lines.append(get_padding_line(node_index, n_columns, edges))
+        lines.append(shift_interline)
+
+        # Make sure that there are as many graph lines as there are
+        # log strings.
+        while len(log_strings) < len(lines):
+            log_strings.append("")
+        if len(lines) < len(log_strings):
+            extra_interline = ["|", " "] * (n_columns + n_columns_diff)
+            while len(lines) < len(log_strings):
+                lines.append(extra_interline)
+
+        # Print lines.
+        indentation_level = max(n_columns, n_columns + n_columns_diff)
+        for (line, logstr) in zip(lines, log_strings):
+            ui.write(format_line(line, indentation_level, logstr))
+
+        # ...and start over.
+        prev_node_index = node_index
+        prev_n_columns_diff = n_columns_diff
+
+cmdtable = {
+    "glog":
+    (graphlog,
+     [("l", "limit", "", _("limit number of changes displayed")),
+      ("p", "patch", False, _("show patch")),
+      ("r", "rev", [], _("show the specified revision or range")),
+      ("", "style", "", _("display using template map file")),
+      ("", "template", "", _("display with template"))],
+     "hg glog [OPTIONS]"),
+}