[cpeterso]

> Hangouts only works in non-Chrome browsers (including ones with WebRTC support) if you install a Google-provided binary blob.

The Google Hangouts website uses some carefully-constructed language to imply that people must download Chrome to use Hangouts, even though a Hangouts NPAPI plugin supposedly exists:

https://www.google.com/hangouts/

  The Hangouts Chrome extension won't work in your current browser. You'll need to
  download Chrome before installing the Hangouts Chrome extension. Do you want to
  download Chrome now?

Google+ photo editing is another Google feature that requires Chrome. I believe it uses NaCL to optimize some photo effects.

[gsnedders]

The NPAPI plugin is the binary blob bz was referring to.

[cpeterso]

The NPAPI plugin is one binary blob. The Chrome extension is another. The Google Hangouts home page only offers the Chrome extension. To actually find the NPAPI installer, you have to know it exists and search for it.