Alternative client to download updates from Windows Update?

I've been trying to work out how to check for and download available updates from Windows Update or WSUS without the official WU clients; for example, there are updates for Windows Embedded that are available through Windows Embedded Developer Update (which uses WU, from what I can tell), but that requires you to register for it, have the WES7 toolkit installed and a WES7 distribution share to even check for available updates, just so you can download a few .cab packages. I know that security updates are released on the MS download site as well, but that's not what I'm looking for, as additional feature packs are only available through WU. They're not on Windows Update Catalog either.

Does anybody know of a custom WU client that you could use to just download update files from WU itself, without actually having the related OS/software installed? So far I haven't found anything, but I don't want to waste time trying to get this to work when there might be something like this already that I've been missing.

 

Hmm... I've looked at those before, but from what I could see they provide downloads for just regular Windows and Office, so I wasn't sure if they could work for my purposes.
On second look, WSUS Offline Update does seem to work similarly to what I need, so maybe I can modify it to include updates for other products as well.

Thanks