I've gotten conflicting reports on this, hoping someone here can tell me. Is there still a way to use PPAPI outside of the NaCl sandbox? The reason I ask is that I work on the open source framework FireBreath and we're investigating ways to deal with Chrome's decision to drop NPAPI. Some of the use cases translate well into NaCl, but unfortunately many of us use plugins currently to provide an interface to proprietary hardware and/or closed-source DLLs, etc that aren't accessible from inside the NaCl sandbox.
My understanding was that PPAPI originally could be used without NaCl and that this is most likely what Flash uses in Chrome; does that capability still exist as an option for those of us for whom none of Chrome's other technologies will solve our issue?
Yes, this capability exists but it is developers only because there is no way to install a trusted PPAPI plugin. Trusted PPAPI plugins must be configured with chrome.exe command line flags. You can also look into Native Messaging API: https://plus.google.com/102860501900098846931/posts/KtawbYAQUGX. May be it fits your requirements.