diff --git a/src/calibre/ebooks/chardet/__init__.py b/src/calibre/ebooks/chardet/__init__.py
index 95a44f8e56..f63805359e 100644
--- a/src/calibre/ebooks/chardet/__init__.py
+++ b/src/calibre/ebooks/chardet/__init__.py
@@ -32,8 +32,8 @@ def detect(aBuf):
 ENCODING_PATS = [
                  re.compile(r'<\?[^<>]+encoding\s*=\s*[\'"](.*?)[\'"][^<>]*>',
                             re.IGNORECASE),
-                 re.compile(r'''<meta\s+?[^<>]*?content\s*=\s*['"][^'"]*?charset=([-a-z0-9]+)[^'"]*?['"][^<>]*>''',
-                            re.IGNORECASE)
+                 re.compile(r'''<meta\s+?[^<>]*?content\s*=\s*['"][^'"]*?charset=([-_a-z0-9]+)[^'"]*?['"][^<>]*>''',
+                            re.IGNORECASE),
                  ]
 ENTITY_PATTERN = re.compile(r'&(\S+?);')
 
diff --git a/src/calibre/library/server/ajax.py b/src/calibre/library/server/ajax.py
index d880ead39b..19db94b984 100644
--- a/src/calibre/library/server/ajax.py
+++ b/src/calibre/library/server/ajax.py
@@ -9,12 +9,17 @@ __docformat__ = 'restructuredtext en'
 
 import json
 from functools import wraps
+from binascii import hexlify, unhexlify
 
 import cherrypy
 
 from calibre.utils.date import isoformat
 from calibre.utils.config import prefs
 from calibre.ebooks.metadata.book.json_codec import JsonCodec
+from calibre.utils.icu import sort_key
+from calibre.library.server import custom_fields_to_display
+from calibre import force_unicode
+from calibre.library.field_metadata import category_icon_map
 
 class Endpoint(object): # {{{
     'Manage mime-type json serialization, etc.'
@@ -48,6 +53,27 @@ class Endpoint(object): # {{{
         return wrapper
 # }}}
 
+def category_icon(category, meta): # {{{
+    if category in category_icon_map:
+        icon = category_icon_map[category]
+    elif meta['is_custom']:
+        icon = category_icon_map['custom:']
+    elif meta['kind'] == 'user':
+        icon = category_icon_map['user:']
+    else:
+        icon = 'blank.png'
+    return icon
+# }}}
+
+def absurl(prefix, url):
+    return prefix + url
+
+def category_url(prefix, cid):
+    return absurl(prefix, '/ajax/category/'+cid)
+
+def icon_url(prefix, name):
+    return absurl(prefix, '/browse/icon/'+name)
+
 class AjaxServer(object):
 
     def __init__(self):
@@ -55,10 +81,23 @@ class AjaxServer(object):
 
     def add_routes(self, connect):
         base_href = '/ajax'
+
+        # Metadata for a particular book
         connect('ajax_book', base_href+'/book/{book_id}', self.ajax_book)
+
+        # The list of top level categories
         connect('ajax_categories', base_href+'/categories',
                 self.ajax_categories)
 
+        # The list of sub-categories and items in each category
+        connect('ajax_category', base_href+'/category/{name}',
+                self.ajax_category)
+
+        # List of books in specified category
+        connect('ajax_books_in', base_href+'/books_in/{category}/{name}',
+                self.ajax_books_in)
+
+
     # Get book metadata {{{
     @Endpoint()
     def ajax_book(self, book_id):
@@ -82,11 +121,8 @@ class AjaxServer(object):
                 'rights', 'book_producer'):
             data.pop(x, None)
 
-        def absurl(url):
-            return self.opts.url_prefix + url
-
-        data['cover'] = absurl(u'/get/cover/%d'%book_id)
-        data['thumbnail'] = absurl(u'/get/thumb/%d'%book_id)
+        data['cover'] = absurl(self.opts.url_prefix, u'/get/cover/%d'%book_id)
+        data['thumbnail'] = absurl(self.opts.url_prefix, u'/get/thumb/%d'%book_id)
         mi.format_metadata = {k.lower():dict(v) for k, v in
                 mi.format_metadata.iteritems()}
         for v in mi.format_metadata.itervalues():
@@ -105,15 +141,216 @@ class AjaxServer(object):
             other_fmts = [x for x in fmts if x != fmt]
         data['formats'] = sorted(fmts)
         if fmt:
-            data['main_format'] = {fmt: absurl(u'/get/%s/%d'%(fmt, book_id))}
+            data['main_format'] = {fmt: absurl(self.opts.url_prefix, u'/get/%s/%d'%(fmt, book_id))}
         else:
             data['main_format'] = None
-        data['other_formats'] = {fmt: absurl(u'/get/%s/%d'%(fmt, book_id)) for fmt
+        data['other_formats'] = {fmt: absurl(self.opts.url_prefix, u'/get/%s/%d'%(fmt, book_id)) for fmt
                 in other_fmts}
 
         return data
     # }}}
 
+    # Top level categories {{{
     @Endpoint()
     def ajax_categories(self):
+        '''
+        Return the list of top-level categories as a list of dictionaries. Each
+        dictionary is of the form::
+            {
+            'name': Display Name,
+            'url':URL that gives the JSON object corresponding to all entries in this category,
+            'icon': URL to icon of this category,
+            'is_category': False for the All Books and Newest categories, True for everything else
+            }
+
+        '''
+        ans = {}
+        categories = self.categories_cache()
+        category_meta = self.db.field_metadata
+
+        def getter(x):
+            return category_meta[x]['name']
+
+        displayed_custom_fields = custom_fields_to_display(self.db)
+
+
+        for category in sorted(categories, key=lambda x: sort_key(getter(x))):
+            if len(categories[category]) == 0:
+                continue
+            if category in ('formats', 'identifiers'):
+                continue
+            meta = category_meta.get(category, None)
+            if meta is None:
+                continue
+            if meta['is_custom'] and category not in displayed_custom_fields:
+                continue
+            display_name = meta['name']
+            if category.startswith('@'):
+                category = category.partition('.')[0]
+                display_name = category[1:]
+            url = hexlify(force_unicode(category).encode('utf-8'))
+            icon = category_icon(category, meta)
+            ans[url] = (display_name, icon)
+
+        ans = [{'url':k, 'name':v[0], 'icon':v[1], 'is_category':True}
+                for k, v in ans.iteritems()]
+        ans.sort(key=lambda x: sort_key(x['name']))
+        for name, url, icon in  [
+                (_('All books'), 'allbooks', 'book.png'),
+                (_('Newest'), 'newest', 'forward.png'),
+                ]:
+            ans.insert(0, {'name':name, 'url':url, 'icon':icon,
+                'is_category':False})
+
+        for c in ans:
+            c['url'] = category_url(self.opts.url_prefix, c['url'])
+            c['icon'] = icon_url(self.opts.url_prefix, c['icon'])
+
+        return ans
+    # }}}
+
+    # Items in the specified category {{{
+    @Endpoint()
+    def ajax_category(self, name, sort='title', num=100, offset=0,
+            sort_order='asc'):
+        try:
+            num = int(num)
+        except:
+            raise cherrypy.HTTPError(404, "Invalid num: %r"%num)
+        try:
+            offset = int(offset)
+        except:
+            raise cherrypy.HTTPError(404, "Invalid offset: %r"%offset)
+
+        base_url = absurl(self.opts.url_prefix, '/ajax/category/'+name)
+
+        if name in ('newest', 'allbooks'):
+            if name == 'newest':
+                sort, sort_order = 'timestamp', 'desc'
+            raise cherrypy.InternalRedirect(
+                '/ajax/books_in/%s/dummy?num=%s&offset=%s&sort=%s&sort_order=%s'%(
+                    name, num, offset, sort, sort_order))
+
+        if sort not in ('rating', 'name', 'popularity'):
+            sort = 'name'
+
+        if sort_order not in ('asc', 'desc'):
+            sort_order = 'asc'
+
+        fm = self.db.field_metadata
+        categories = self.categories_cache()
+        hierarchical_categories = self.db.prefs['categories_using_hierarchy']
+
+        if name in categories:
+            toplevel = name
+            subcategory = None
+        else:
+            try:
+                subcategory = unhexlify(name)
+            except:
+                raise cherrypy.HTTPError(404, 'Invalid category id: %r'%name)
+            toplevel = subcategory.partition('.')[0]
+            if toplevel == subcategory:
+                subcategory = None
+        if toplevel not in categories or toplevel not in fm:
+            raise cherrypy.HTTPError(404, 'Category %r not found'%toplevel)
+
+        # Find items and sub categories
+        subcategories = []
+        meta = fm[toplevel]
+        item_names = {}
+
+        if meta['kind'] == 'user':
+            fullname = ((toplevel + '.' + subcategory) if subcategory is not
+                                None else toplevel)
+            try:
+                # User categories cannot be applied to books, so this is the
+                # complete set of items, no need to consider sub categories
+                items = categories[fullname]
+            except:
+                raise cherrypy.HTTPError(404,
+                        'User category %r not found'%fullname)
+
+            parts = fullname.split('.')
+            for candidate in categories:
+                cparts = candidate.split('.')
+                if len(cparts) == len(parts)+1 and cparts[:-1] == parts:
+                    subcategories.append({'name':cparts[-1],
+                        'url':candidate,
+                        'icon':category_icon(toplevel, meta)})
+
+            category_name = toplevel[1:].split('.')
+            # When browsing by user categories we ignore hierarchical normal
+            # columns, so children can be empty
+            children = set()
+
+        elif toplevel in hierarchical_categories:
+            items = []
+
+            category_names = [x.original_name.split('.') for x in categories[toplevel] if
+                    '.' in x.original_name]
+
+            if subcategory is None:
+                children = set(x[0] for x in category_names)
+                category_name = [meta['name']]
+                items = [x for x in categories[toplevel] if '.' not in x.original_name]
+            else:
+                subcategory_parts = subcategory.split('.')[1:]
+                category_name = [meta['name']] + subcategory_parts
+
+                lsp = len(subcategory_parts)
+                children = set('.'.join(x) for x in category_names if len(x) ==
+                        lsp+1 and x[:lsp] == subcategory_parts)
+                items = [x for x in categories[toplevel] if x.original_name in
+                        children]
+                item_names = {x:x.original_name.rpartition('.')[-1] for x in
+                        items}
+                # Only mark the subcategories that have children themselves as
+                # subcategories
+                children = set('.'.join(x[:lsp+1]) for x in category_names if len(x) >
+                        lsp+1 and x[:lsp] == subcategory_parts)
+            subcategories = [{'name':x.rpartition('.')[-1],
+                'url':hexlify(toplevel+'.'+x),
+                'icon':category_icon(toplevel, meta)} for x in children]
+
+        for x in subcategories:
+            x['url'] = category_url(self.opts.url_prefix, x['url'])
+            x['icon'] = icon_url(self.opts.url_prefix, x['icon'])
+
+        sort_keygen = {
+                'name': lambda x: sort_key(x.sort if x.sort else x.original_name),
+                'popularity': lambda x: x.count,
+                'rating': lambda x: x.avg_rating
+        }
+        items.sort(key=sort_keygen[sort], reverse=sort_order == 'desc')
+        total_num = len(items)
+        items = items[offset:offset+num]
+        items = [{
+            'name':item_names.get(x, x.original_name),
+            'average_rating': x.avg_rating,
+            'count': x.count,
+            'url': absurl(self.opts.url_prefix, '/ajax/books_in/%s/%s'%(
+                hexlify(toplevel), hexlify(x.original_name))),
+            'has_children': x.original_name in children,
+            } for x in items]
+
+        return {
+                'category_name': category_name,
+                'base_url': base_url,
+                'total_num': total_num,
+                'offset':offset, 'num':num, 'sort':sort,
+                'sort_order':sort_order,
+                'subcategories':subcategories,
+                'items':items,
+        }
+
+
+    # }}}
+
+    # Books in the specified category {{{
+    @Endpoint()
+    def ajax_books_in(self, name, item, sort='title', num=100, offset=0,
+            sort_order='asc'):
         pass
+    # }}}
+