diff --git a/tools/build/build.py b/tools/build/build.py
index f32b72c9..0cc8531b 100755
--- a/tools/build/build.py
+++ b/tools/build/build.py
@@ -9,9 +9,10 @@ import re
 import shutil
 import subprocess
 import sys
+import tarfile
 import time
 
-def build_oxjs(geo):
+def build_oxjs(downloads=False, geo=False):
 
     base_path = os.path.dirname(__file__)
     if base_path:
@@ -27,7 +28,7 @@ def build_oxjs(geo):
         stdout=subprocess.PIPE
     ).communicate()[0].strip()
     year = time.strftime('%Y', time.gmtime())
-    comment = 'OxJS %s (c) %s 0x2620, dual-licensed GPL/MIT, see https://oxjs.org for details' % (version, year)
+    comment = ' OxJS %s (c) %s 0x2620, dual-licensed GPL/MIT, see https://oxjs.org for details ' % (version, year)
 
     # SVGs
     path = source_path + 'Ox.UI/themes/classic/svg/'
@@ -144,14 +145,14 @@ def build_oxjs(geo):
     data = {
         # sum(list, []) is flatten
         'documentation': sorted(sum(ox_files, [])) + sorted(filter(
-            lambda x: re.match('.+\.js$', x),
+            lambda x: re.search('\.js$', x),
             ui_files['dev']
         ) + map(
             lambda x: 'Ox.%s/Ox.%s.js' % (x, x),
             ['Geo', 'Image', 'Unicode']
         )),
         'examples': filter(
-            lambda x: not re.match('^\.', x),
+            lambda x: not re.search('^\.', x),
             os.listdir(root_path + 'examples/')
         ),
         'readme': map(
@@ -163,18 +164,49 @@ def build_oxjs(geo):
                 'name': x.split('.')[0]
             },
             filter(
-                lambda x: not re.match('^[\._]', x),
+                lambda x: not re.search('^[\._]', x),
                 os.listdir(root_path + 'readme/html/')
             )
-        )
+        ),
+        'version': version
     }
     write_file(root_path + 'index.json', json.dumps(data, indent=4, sort_keys=True))
 
+    # downloads
+    if downloads:
+        # source
+        download_path = root_path + 'downloads/'
+        source_file = 'OxJS.%s.source.tar.gz' % version
+        source_tar = tarfile.open(download_path + source_file, 'w:gz')
+        source_tar.add(root_path, arcname='OxJS', filter=filter_source)
+        source_tar.close()
+        write_link(source_file, root_path + 'downloads/OxJS.latest.source.tar.gz')
+        # build
+        build_file = 'OxJS.%s.build.tar.gz' % version
+        build_tar = tarfile.open(download_path + build_file, 'w:gz')
+        build_tar.add(root_path, arcname='OxJS', filter=filter_build)
+        build_tar.close()
+        write_link(build_file, root_path + 'downloads/OxJS.latest.build.tar.gz')
+
 
 def copy_file(source, target):
     print 'copying', source, 'to', target
     write_file(target, read_file(source))
 
+def filter_build(tarinfo):
+    if tarinfo.name == 'OxJS':
+        return tarinfo
+    if re.search('^OxJS/build', tarinfo.name):
+        return tarinfo
+    return None
+
+def filter_source(tarinfo):
+    if re.search('^OxJS/(demos|downloads/|tools/geo/png/icons/)', tarinfo.name):
+        return None
+    if re.search('/[\._]', tarinfo.name):
+        return None
+    return tarinfo
+
 def read_file(file):
     print 'reading', file
     f = open(file)
@@ -204,5 +236,4 @@ def write_path(file):
 
 
 if __name__ == '__main__':
-    geo = False if sys.argv[-1] == '-nogeo' else True
-    build_oxjs(geo)
+    build_oxjs(downloads='-downloads' in sys.argv, geo=not '-nogeo' in sys.argv)