URLs of the index files used by the software update client on OS X

osx-software-update-urls.txt

10.3 (Panther):
https://swscan.apple.com/scanningpoints/scanningpointX.xml

10.4 (Tiger):
https://swscan.apple.com/content/catalogs/index.sucatalog
https://swscan.apple.com/content/catalogs/index-1.sucatalog

10.5 (Leopard):
https://swscan.apple.com/content/catalogs/others/index-leopard.merged-1.sucatalog

10.6 (Snow Leopard):
https://swscan.apple.com/content/catalogs/others/index-leopard-snowleopard.merged-1.sucatalog

10.7 (Lion):
https://swscan.apple.com/content/catalogs/others/index-lion-snowleopard-leopard.merged-1.sucatalog

10.8 (Mountain Lion):
https://swscan.apple.com/content/catalogs/others/index-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.8 (Mountain Lion incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-mountainlionseed-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.9 (Mavericks):
https://swscan.apple.com/content/catalogs/others/index-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.9 (Mavericks incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.9seed-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.10 (Yosemite):
https://swscan.apple.com/content/catalogs/others/index-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (Yosemite incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.10seed-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (Yosemite Beta Program):
https://swscan.apple.com/content/catalogs/others/index-10.10beta-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.11 (El Capitan):
https://swscan.apple.com/content/catalogs/others/index-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (El Capitan incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.11seed-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.11 (El Capitan Beta Program):
https://swscan.apple.com/content/catalogs/others/index-10.11beta-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog


-------------------------------------
For Reposado (edit reposadocommon.py)
-------------------------------------

# ('http://swscan.apple.com/scanningpoints/scanningpointX.xml'), # 10.3
  ('https://swscan.apple.com/content/catalogs/index.sucatalog'), # 10.4
  ('https://swscan.apple.com/content/catalogs/index-1.sucatalog'), # 10.4
  ('https://swscan.apple.com/content/catalogs/others/index-leopard.merged-1.sucatalog'), # 10.5
  ('https://swscan.apple.com/content/catalogs/others/index-leopard-snowleopard.merged-1.sucatalog'), # 10.6
  ('https://swscan.apple.com/content/catalogs/others/index-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.7
  ('https://swscan.apple.com/content/catalogs/others/index-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.8
  ('https://swscan.apple.com/content/catalogs/others/index-mountainlionseed-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.8
  ('https://swscan.apple.com/content/catalogs/others/index-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.9
  ('https://swscan.apple.com/content/catalogs/others/index-10.9seed-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.9
  ('https://swscan.apple.com/content/catalogs/others/index-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.10beta-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.10seed-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11
  ('https://swscan.apple.com/content/catalogs/others/index-10.11beta-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11
  ('https://swscan.apple.com/content/catalogs/others/index-10.11seed-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11

Please update this when OS X 10.12 hits!

Also: the "incl. seeds" releases should be specified as "Dev betas" instead. With El Capitan, Apple pushed two beta channels, public and dev. They're mostly the same, but sometimes the public channel gets updates a day or two later.

"Beta program" is rather ambiguous as there are two channels (explained above) used for updates now.

The only "seed" program I remember was Mavericks, back when Apple still used the appleseed.apple.com domain.

10.12 (macOS Sierra seed) https://swscan.apple.com/content/catalogs/others/index-10.12seed-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz

https://swscan.apple.com/content/catalogs/others/index-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

High Sierra: https://swscan.apple.com/content/catalogs/others/index-10.13seed-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz

What about 10.14

Mojave: https://swscan.apple.com/content/catalogs/others/index-10.14seed-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz

Catalina: https://swscan.apple.com/content/catalogs/others/index-10.15seed-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz