diff --git a/hgext/bookmarks.py b/hgext/bookmarks.py
--- a/hgext/bookmarks.py
+++ b/hgext/bookmarks.py
@@ -5,7 +5,7 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
-'''mercurial bookmarks
+'''Mercurial bookmarks
 
 Mercurial bookmarks are local moveable pointers to changesets. Every
 bookmark points to a changeset identified by its hash. If you commit a
@@ -112,7 +112,7 @@ def setcurrent(repo, mark):
     repo._bookmarkcurrent = mark
 
 def bookmark(ui, repo, mark=None, rev=None, force=False, delete=False, rename=None):
-    '''mercurial bookmarks
+    '''Mercurial bookmarks
 
     Bookmarks are pointers to certain commits that move when
     commiting. Bookmarks are local. They can be renamed, copied and
diff --git a/hgext/hgk.py b/hgext/hgk.py
--- a/hgext/hgk.py
+++ b/hgext/hgk.py
@@ -12,7 +12,7 @@ graphical way. It requires Tcl/Tk versio
 distributed with Mercurial.)
 
 hgk consists of two parts: a Tcl script that does the displaying and
-querying of information, and an extension to mercurial named hgk.py,
+querying of information, and an extension to Mercurial named hgk.py,
 which provides hooks for hgk to get information. hgk can be found in
 the contrib directory, and hgk.py can be found in the hgext directory.
 
diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -1645,7 +1645,7 @@ def delete(ui, repo, *patches, **opts):
     -r/--rev parameter. At least one patch or revision is required.
 
     With --rev, mq will stop managing the named revisions (converting
-    them to regular mercurial changesets). The qfinish command should
+    them to regular Mercurial changesets). The qfinish command should
     be used as an alternative for qdelete -r, as the latter option is
     deprecated.
 
@@ -1753,7 +1753,7 @@ def clone(ui, source, dest=None, **opts)
     Source patch repository is looked for in <src>/.hg/patches by
     default. Use -p <url> to change.
 
-    The patch directory must be a nested mercurial repository, as
+    The patch directory must be a nested Mercurial repository, as
     would be created by qinit -c.
     '''
     def patchdir(repo):
diff --git a/hgext/win32mbcs.py b/hgext/win32mbcs.py
--- a/hgext/win32mbcs.py
+++ b/hgext/win32mbcs.py
@@ -39,7 +39,7 @@ To use this extension, enable the extens
   hgext.win32mbcs =
 
 Path encoding conversion are done between Unicode and
-encoding.encoding which is decided by mercurial from current locale
+encoding.encoding which is decided by Mercurial from current locale
 setting or HGENCODING.
 
 """
diff --git a/hgext/zeroconf/__init__.py b/hgext/zeroconf/__init__.py
--- a/hgext/zeroconf/__init__.py
+++ b/hgext/zeroconf/__init__.py
@@ -5,7 +5,7 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
-'''zeroconf support for mercurial repositories
+'''zeroconf support for Mercurial repositories
 
 Zeroconf enabled repositories will be announced in a network without
 the need to configure a server or a service. They can be discovered
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1728,7 +1728,7 @@ def import_(ui, repo, patch1, *patches, 
                 wp = repo.parents()
                 if opts.get('exact'):
                     if not nodeid or not p1:
-                        raise util.Abort(_('not a mercurial patch'))
+                        raise util.Abort(_('not a Mercurial patch'))
                     p1 = repo.lookup(p1)
                     p2 = repo.lookup(p2 or hex(nullid))