diff --git a/src/download_itunes.py b/src/download_itunes.py
index 2e1a4ec..2de98ea 100755
--- a/src/download_itunes.py
+++ b/src/download_itunes.py
@@ -33,6 +33,16 @@ def enum_genres(bundle_id):
             yield lang, gid, name
 
 
+def choose_lang(obj):
+    ''' expects dict with {'us': ..., 'de': ...} '''
+    for lang in AVAILABLE_LANGS:
+        try:
+            return obj[lang]
+        except KeyError:
+            pass
+    return None
+
+
 def download_info(bundle_id, lang, force=False):
     fname = fname_for(bundle_id, lang)
     if force or not mylib.file_exists(fname):
diff --git a/src/html_categories.py b/src/html_categories.py
index 28c58d0..c189a2a 100755
--- a/src/html_categories.py
+++ b/src/html_categories.py
@@ -21,7 +21,7 @@ def process(affected=None, per_page=60):
         print('  {} ({})'.format(cat, a))
 
     print('  .. {} categories'.format(len(arr)))
-    src = ''.join([HTML.a(n, '{}/'.format(cid)) for cid, n in arr])
+    src = ''.join([HTML.a_category(cid, n) for cid, n in arr])
     HTML.write(base, '''
 <h2>{}</h2>
 <div class="tags large center">
diff --git a/src/index_app_names.py b/src/index_app_names.py
index d9089ff..c2df442 100755
--- a/src/index_app_names.py
+++ b/src/index_app_names.py
@@ -4,67 +4,58 @@ import sys
 import lib_common as mylib
 import download_itunes  # app_names
 
-_bundle_name_dict = None
+_app_names_dict = None
 
 
-def index_fname():
-    return mylib.path_data_index('app_names.json')
+def fname_apps_all():
+    return mylib.path_data_index('app_names_all.json')
 
 
-def missing():
-    return not mylib.file_exists(index_fname())
+def fname_apps_compact():
+    return mylib.path_data_index('app_names_compact.json')
 
 
-def load_json_if_not_already():
-    global _bundle_name_dict
-    if not _bundle_name_dict:
-        index_file = index_fname()
-        if mylib.file_exists(index_file):
-            _bundle_name_dict = mylib.json_read(index_file)
-        else:
-            _bundle_name_dict = {}
-
-
-def write_json_to_disk():
-    mylib.json_write(index_fname(), _bundle_name_dict, pretty=False)
-
-
-def get_name(bundle_id, langs=['us', 'de'], fallback='&lt; App-Name &gt;'):
-    load_json_if_not_already()
-    for lang in langs:
-        try:
-            return _bundle_name_dict[bundle_id][lang]
-        except KeyError:
-            continue
-    return fallback  # None
+def get_name(bundle_id, fallback='&lt; App-Name &gt;'):
+    global _app_names_dict
+    if not _app_names_dict:
+        _app_names_dict = mylib.json_safe_read(fname_apps_compact(), {})
+    try:
+        return _app_names_dict[bundle_id]
+    except KeyError:
+        return fallback
 
 
 def process(bundle_ids, deleteOnly=False):
+    global _app_names_dict
     print('writing index: app names ...')
     if bundle_ids == ['*']:
         print('  full reset')
-        mylib.rm_file(index_fname())  # rebuild from ground up
+        mylib.rm_file(fname_apps_all())  # rebuild from ground up
+        mylib.rm_file(fname_apps_compact())
 
-    load_json_if_not_already()
+    index = mylib.json_safe_read(fname_apps_all(), {})
     did_change = False
     for bid in mylib.appids_in_data(bundle_ids):
         if deleteOnly:
-            did_change |= mylib.try_del(_bundle_name_dict, [bid])
+            did_change |= mylib.try_del(index, [bid])
             continue
         names = download_itunes.get_app_names(bid)
         if not names:
             mylib.err('index-app-names', 'could not load: {}'.format(bid))
             continue
         try:
-            if _bundle_name_dict[bid] == names:
+            if index[bid] == names:
                 continue
         except KeyError:
             pass
-        _bundle_name_dict[bid] = names
+        index[bid] = names
         did_change = True
     if did_change:
         print('  writing')
-        write_json_to_disk()
+        mylib.json_write(fname_apps_all(), index, pretty=False)
+        _app_names_dict = {bid: download_itunes.choose_lang(names)
+                           for bid, names in index.items()}
+        mylib.json_write(fname_apps_compact(), _app_names_dict, pretty=False)
     else:
         print('  no change')
     print('')
diff --git a/src/index_categories.py b/src/index_categories.py
index 694522f..22545c3 100755
--- a/src/index_categories.py
+++ b/src/index_categories.py
@@ -12,50 +12,53 @@ def fname_app_categories():
     return mylib.path_data_index('app_categories.json')
 
 
-def fname_category_names():
-    return mylib.path_data_index('category_names.json')
+def fname_cat_name_all():
+    return mylib.path_data_index('category_names_all.json')
 
 
-def load_json_if_not_already():
-    def load_json_from_disk(fname):
-        return mylib.json_read(fname) if mylib.file_exists(fname) else {}
+def fname_cat_name_compact():
+    return mylib.path_data_index('category_names_compact.json')
 
+
+def load_json_if_not_already(noNames=False):
     global _dict_apps, _dict_names
     if not _dict_apps:
-        _dict_apps = load_json_from_disk(fname_app_categories())
-    if not _dict_names:
-        _dict_names = load_json_from_disk(fname_category_names())
+        _dict_apps = mylib.json_safe_read(fname_app_categories(), {})
+    if not _dict_names and not noNames:
+        _dict_names = mylib.json_safe_read(fname_cat_name_compact(), {})
 
 
-def try_update_app(bid, genre_ids):
+def try_update_app(index, bid, genre_ids):
     try:
-        if _dict_apps[bid] == genre_ids:
+        if index[bid] == genre_ids:
             return False
     except KeyError:
         pass
-    _dict_apps[bid] = genre_ids
+    index[bid] = genre_ids
     return True
 
 
-def try_update_name(gid, lang, name):
+def try_update_name_all(index, cid, lang, name):
     try:
-        _dict_names[gid]
+        index[cid]
     except KeyError:
-        _dict_names[gid] = {}
+        index[cid] = {}
     try:
-        if _dict_names[gid][lang]:
+        if index[cid][lang]:
             return False  # key already exists
     except KeyError:
         pass
-    _dict_names[gid][lang] = name
+    index[cid][lang] = name
     return True  # updated, need to persist changes
 
 
 def reset_index():
-    global _dict_apps
-    print('  full reset')
+    global _dict_apps, _dict_names
     mylib.rm_file(fname_app_categories())  # rebuild from ground up
+    mylib.rm_file(fname_cat_name_all())
+    mylib.rm_file(fname_cat_name_compact())
     _dict_apps = None
+    _dict_names = None
 
 
 def get_categories(bundle_id):
@@ -66,13 +69,7 @@ def get_categories(bundle_id):
         return []
     res = []
     for gid in genres:
-        for lang in ['us', 'de']:
-            try:
-                name = _dict_names[gid][lang]
-            except KeyError:
-                continue
-            res.append((gid, name))
-            break
+        res.append((gid, _dict_names[gid]))
     return res
 
 
@@ -85,40 +82,40 @@ def enum_all_categories():
                 reverse_index[gid].append(bid)
             except KeyError:
                 reverse_index[gid] = [bid]
-    for gid, lang_dict in _dict_names.items():
-        for lang in ['us', 'de']:
-            try:
-                name = lang_dict[lang]
-            except KeyError:
-                continue
-            yield gid, name, reverse_index[gid]
-            break
+    for gid, name in _dict_names.items():
+        yield gid, name, reverse_index[gid]
 
 
 def process(bundle_ids, force=False):
+    global _dict_apps, _dict_names
     print('writing index: categories ...')
     if force and bundle_ids == ['*']:
+        print('  full reset')
         reset_index()
 
-    load_json_if_not_already()
+    load_json_if_not_already(noNames=False)
+    name_index = mylib.json_safe_read(fname_cat_name_all(), {})
     write_name_index = False
     write_app_index = False
     for bid in mylib.appids_in_data(bundle_ids):
-        genre_ids = []
-        for lang, gid, gname in download_itunes.enum_genres(bid):
-            if gid not in genre_ids:
-                genre_ids.append(gid)
-            if try_update_name(gid, lang, gname):
+        cateogory_ids = []
+        for lang, cid, gname in download_itunes.enum_genres(bid):
+            if cid not in cateogory_ids:
+                cateogory_ids.append(cid)
+            if try_update_name_all(name_index, cid, lang, gname):
                 write_name_index = True
-        if try_update_app(bid, genre_ids):
+        if try_update_app(_dict_apps, bid, cateogory_ids):
             write_app_index = True
 
-    if write_name_index:
-        print('  write name-index')
-        mylib.json_write(fname_category_names(), _dict_names, pretty=False)
     if write_app_index:
         print('  write app-index')
         mylib.json_write(fname_app_categories(), _dict_apps, pretty=False)
+    if write_name_index:
+        print('  write name-index')
+        mylib.json_write(fname_cat_name_all(), name_index, pretty=False)
+        _dict_names = {cid: download_itunes.choose_lang(names)
+                       for cid, names in name_index.items()}
+        mylib.json_write(fname_cat_name_compact(), _dict_names, pretty=False)
     print('')
 
 
diff --git a/src/index_domains.py b/src/index_domains.py
index 6101280..4030d67 100755
--- a/src/index_domains.py
+++ b/src/index_domains.py
@@ -15,10 +15,8 @@ def fname_tracker():
 
 
 def load_json_from_disk(index_file):
-    if mylib.file_exists(index_file):
-        return mylib.json_read(index_file)
-    else:
-        return {'bundle': [], 'pardom': {}, 'subdom': {}}
+    return mylib.json_safe_read(
+        index_file, fallback={'bundle': [], 'pardom': {}, 'subdom': {}})
 
 
 def delete_from_index(index, bundle_ids, deleteOnly=False):
diff --git a/src/index_meta.py b/src/index_meta.py
index 62849c5..4da92eb 100755
--- a/src/index_meta.py
+++ b/src/index_meta.py
@@ -13,10 +13,6 @@ def fname_app_rank():
     return mylib.path_data_index('app_rank.json')
 
 
-def load_json_from_disk(fname):
-    return mylib.json_read(fname) if mylib.file_exists(fname) else {}
-
-
 def json_to_list(json):
     return [
         json['sum_rec'],
@@ -100,7 +96,7 @@ def write_rank_index(index):
 
 def get_total_counts():
     try:
-        return load_json_from_disk(fname_app_summary())['_sum']
+        return mylib.json_safe_read(fname_app_summary(), {})['_sum']
     except KeyError:
         return [0, 0]
 
@@ -112,7 +108,7 @@ def process(bundle_ids, deleteOnly=False):
         print('  full reset')
         mylib.rm_file(fname)  # rebuild from ground up
 
-    index = load_json_from_disk(fname)
+    index = mylib.json_safe_read(fname, {})
     ids = mylib.appids_in_data(bundle_ids)
     write_summary_index(index, ids, deleteOnly=deleteOnly)
     write_rank_index(index)
diff --git a/src/lib_common.py b/src/lib_common.py
index 7464086..cd4f377 100755
--- a/src/lib_common.py
+++ b/src/lib_common.py
@@ -249,14 +249,14 @@ def enum_jsons(bundle_id):
             yield fname, json.load(fp)
 
 
-def appids_in_out(selection=['*']):
-    if selection != ['*']:
+def appids_in_out(selection=None):
+    if selection and selection != ['*']:
         return selection
     return [os.path.basename(x) for x in glob.glob(path_out_app('*'))]
 
 
-def appids_in_data(selection=['*']):
-    if selection != ['*']:
+def appids_in_data(selection=None):
+    if selection and selection != ['*']:
         return selection
     global _all_data_bundle_ids
     if not _all_data_bundle_ids:
@@ -287,6 +287,10 @@ def json_read(path):
         return json.load(fp)
 
 
+def json_safe_read(path, fallback=None):
+    return json_read(path) if file_exists(path) else fallback
+
+
 def json_write(path, obj, pretty=False):
     with open(path, 'w') as fp:
         json.dump(obj, fp, indent=2 if pretty else None, sort_keys=pretty)
diff --git a/src/lib_graphs.py b/src/lib_graphs.py
index 87be7c9..1a4fe11 100755
--- a/src/lib_graphs.py
+++ b/src/lib_graphs.py
@@ -13,11 +13,11 @@ def percent_bar(percent):
     return '<div class="pcbar"><i style="left: {}%"></i></div>'.format(round(percent * 100))
 
 
-def rank_tile(title, value, additional=None, attr={},
+def rank_tile(title, value, additional=None, attr=None,
               percent=0.5, rank='?', best='?', worst='?'):
     if additional:
         value += '<i class="snd mg_lr">({})</i>'.format(additional)
-    attr = HTML.attr_and(attr, {'class': 'rank'})
+    attr = HTML.attr_and(attr or {}, {'class': 'rank'})
     return HTML.div('''
 <h4>{}</h4>
 {} <b class="mg_lr">{}</b>
diff --git a/src/lib_html.py b/src/lib_html.py
index 2882ec7..57b3541 100755
--- a/src/lib_html.py
+++ b/src/lib_html.py
@@ -46,29 +46,27 @@ def attr_and(a, b):
 
 # Basic building blocks
 
-def xml(tag, inner, attr={}):
+def xml(tag, inner, attr=None):
     src = ''
-    for key, val in attr.items():
-        if val:
-            src += ' {}="{}"'.format(key, val)
+    if attr:
+        for key, val in attr.items():
+            if val:
+                src += ' {}="{}"'.format(key, val)
     return '<{0}{1}>{2}</{0}>'.format(tag, src, inner)
 
 
-def div(inner, attr={}):
+def div(inner, attr=None):
     return xml('div', inner, attr)
 
 
-def h2(inner, attr={}):
+def h2(inner, attr=None):
     return xml('h2', inner, attr)
 
 
-def a(inner, href, attr={}):
-    return xml('a', inner, attr_and(attr, {'href': href}))
-
-
 def a_path(parts, suffix):
     ''' expects (name, url) tuples '''
-    return ' / '.join([a(*x) for x in parts] + [suffix])
+    return ' / '.join(['<a href="{}/">{}</a>'.format(url, title)
+                       for title, url in parts] + [suffix])
 
 
 # Simple constructs
@@ -137,8 +135,8 @@ def app_tile_template():
 </div></a>'''
 
 
-def app_tiles_all(bundle_ids, per_page=60, attr={}):
-    attr = attr_and(attr, {'id': 'app-toc', 'class': 'no-ul-all'})
+def app_tiles_all(bundle_ids, per_page=60):
+    attr = {'id': 'app-toc', 'class': 'no-ul-all'}
     c_apps = len(bundle_ids)
     c_pages = int(math.ceil(c_apps / per_page))
     for i, apps in apps_sorted_batch(bundle_ids, batch_size=per_page):
@@ -170,11 +168,11 @@ def write(path, content, title=None, fname='index.html'):
         fp.write(base_template(content, title=title))
 
 
-def write_app_pages(base, bundle_ids, title, per_page=60, attr={}, pre=''):
+def write_app_pages(base, bundle_ids, title, per_page=60, pre=''):
     pages = 0
     entries = 0
     mylib.rm_dir(base)
-    for i, count, src in app_tiles_all(bundle_ids, per_page, attr):
+    for i, count, src in app_tiles_all(bundle_ids, per_page):
         pages += 1
         entries += count
         pth = base if i == 1 else mylib.path_add(base, str(i))