And my question is: which do and which don't?

Somehow Peter Beverlo can generate that list for Chromium automatically.

Can opera do the same somewhere?

Or supporting opera--help or man opera with up-to date info would be a good start.

Does Opera support the --headless switch properly, or will Opera support --headless in the future, like chromium and chrome.

I tried it on Opera Developer/Beta, it runs, it hides the main window, doesn't show anything except the menu

Is there a list of all command line switches available for Opera, something like
http://peter.sh/experiments/chromium-command-line-switches/

opera-developer --help doesn't help much.

[code]We lowered flash requirements to version 23, so Linux users don’t have to install the latest flash."[/code]

Doesn't that mean that you allow flash versions with known and unpatched vulnerabilities.

Unfortunately the link preview/hover/popup in the bottomleft corner is gone.

Internet feels a lot unsafer, if you don't know where you go.

Missing it a lot.

Great, crashing immediately. From the fastest to the slowest, doesn't move at all, doesn't start.

Same problem as described on the blog. I use Opera Developer to develop and try out extensions. No more I guess, forced to be on hold.

Known issue, I don't like the attitude shipping products in this state, it's disrespectful to other software, forcing a user to remove Chromium. Better skip a version, if you can't make it work.

Hopefully it will be fixed soon.

@shwetankdixit, I don't see anything about Linux mentioned in the documentation.

On my DNA-23526 bug-report I got this answer:

Could you try using following paths
/etc/chromium/native-messaging-hosts
or:
<OPERA_PROFILE_DIR>/NativeMessagingHosts
Profile path will be displayed on opera:about page.`

Opera:about doesn't show anything about a google-chrome path, but mentioned path worked at that moment. Please don't blame me for filing more bug reports when it stopped working. The path really changed between versions, without documentation or rationale.

And it feels wrong and risky:
If Google-Chrome isn't installed, the google-chrome path is a path any program can create/write to.

And when you have Chrome installed and decide to drop it because you prefer Opera, and remove Chrome and all of it's settings, suddenly Opera fails. Doesn't make sense to me.

@kszularz thx, maybe this can help, the bugs I filed on this issue:

• DNA-23526
• DNA-43909
• DNAWIZ-3730

I agree, the documentation seems to be copied, and not updated. I can't imagine the path for a manifest should be a google path instead of it's own .config/opera path, although I agree that is reality, but I consider this a bug.

What happens when you install your extensions, I can get them working using the Google Chrome path for the manifest.

Yes, Opera uses the path for Google Chrome to look for manifests:

~/.config/google-chrome/NativeMessagingHosts

Now I know why the example works, I had it also installed in Google Chrome, not my own extensions. When I place the manifest in above Google Chrome location the extension starts working.

Will file another bug report, pfff.

I agree, it is broken. It was broken, I filed a bug report. DNA-23526, They fixed it.
Then it broke again sometime, at least for extensions in developer mode, same extension works in Chromium, it doesn't in Opera. Mostly on error ***Can't find manifest for native messaging host com.my_company.my_application, while it's there. I field another bug report, but no fix DNA-43909. Since then I use Chromium a bit more.

To debug

• start Opera from terminal, it will give you some errors in terminal.
• Try the official example.
  Strangely that one works in Opera, while my own do not work in Opera, but they do work in Chromium.

Path to manifest (I use it in opera-developer).

• On Linux: ~/.config/opera-developer/NativeMessagingHosts/com.my_company.my_application.json
• On OSX (I guess): ~/Library/Application Support/Opera/NativeMessagingHosts/com.my_company.my_application.json
• for chromium: ~/.config/chromium/NativeMessagingHosts/com.my_company.my_application.json

Annoyingly, there is no error message, when you have set the extension ID wrong

"allowed_origins": [ "chrome-extension://xxx/" ]