
Firefox Replay - nachtigall
https://firefox-replay.com/
======
darshan
Mods: the link should perhaps be changed to:
[https://developer.mozilla.org/en-
US/docs/Mozilla/Projects/We...](https://developer.mozilla.org/en-
US/docs/Mozilla/Projects/WebReplay)

This currently has 1215 points, and the link is no longer valid. It now just
shows an image of Firefox's devtools and the sentence "Replay is an early
experiment. We'll let you know on @FirefoxDevTools when it's ready for input."
That's not useful, interesting, or informative. The MDN docs seem like an
appropriate replacement.

~~~
dessant
The initial version of the site gave a good overview of Firefox Replay:
[https://web.archive.org/web/20191128111509/https://firefox-r...](https://web.archive.org/web/20191128111509/https://firefox-
replay.com/)

~~~
Narushia
That gives me “The Wayback Machine has not archived that URL.”

I also get the same for all the other snapshots, maybe Mozilla applied for a
takedown?

Edit: I found it on archive.is:
[http://archive.is/0ei35](http://archive.is/0ei35) Though it seems a bit
broken.

~~~
dessant
You can also use my browser extension [1] to quickly find the original version
of the site in other places:

[https://megalodon.jp/2019-1128-2050-51/https://firefox-
repla...](https://megalodon.jp/2019-1128-2050-51/https://firefox-
replay.com:443/)

[http://cc.bingj.com/cache.aspx?q=url:https%3A%2F%2Ffirefox-r...](http://cc.bingj.com/cache.aspx?q=url:https%3A%2F%2Ffirefox-
replay.com%2F&d=4637856076988454&mkt=en-WW&setlang=en-
US&w=-rUAvVyll0c9DeiDtD0UxEivsNUOE-Nm)

[http://cache.yahoofs.jp/search/cache?c=ULQkH25vOxAJ&p=https%...](http://cache.yahoofs.jp/search/cache?c=ULQkH25vOxAJ&p=https%3A%2F%2Ffirefox-
replay.com%2F&u=https%3A%2F%2Ffirefox-replay.com%2F)

[http://210.89.172.69/search2.naver?group=web&mtype=web_doc&w...](http://210.89.172.69/search2.naver?group=web&mtype=web_doc&where=web_html&from=webkr&u=https%3A%2F%2Ffirefox-
replay.com%2F&r=1&docid=a00000fa_eca2899c556f1179fdaa8f92&rev=31&tl=firefox-
replay.com%2F%2C+.firefox-replay.com%2F)

[1] [https://github.com/dessant/view-page-
archive](https://github.com/dessant/view-page-archive)

~~~
dewey
This is a really cool extension, thanks for sharing!

------
inglor
This is a pretty nice comment from the source that explains how it works:
[https://github.com/mozilla/gecko-
dev/blob/11d9c7b7fa82fdfb8a...](https://github.com/mozilla/gecko-
dev/blob/11d9c7b7fa82fdfb8ac2a8f0864e9d8d5fe2b926/mfbt/RecordReplay.h#L32-L73)

``` // Recording and replaying works by controlling non-determinism in the
browser:

// non-deterministic behaviors are initially recorded, then later replayed

// exactly to force the browser to behave deterministically. Two types of

// non-deterministic behaviors are captured: intra-thread and inter-thread.

// Intra-thread non-deterministic behaviors are non-deterministic even in the

// absence of actions by other threads, and inter-thread non-deterministic

// behaviors are those affected by interleaving execution with other threads.

```

~~~
cocochanel
What is non-determinism in the browser?

~~~
Jyaif
Once source comes from the memory allocator, and the pointers it gives out.

If you have an ordered map of pointers (e.g. std::map<void*>), iterating over
the map will not be deterministic because the pointers given by a (regular)
allocator are not deterministic.

~~~
dgoldstein0
This may be true in c++ but I believe is not in JavaScript. The language
defines iteration order over keys of an object to be the insertion order
(except numeric keys which are in ascending order). Not sure if there's
anywhere that iteration order is actually nondeterministic that's allowed by
the spec.

------
strombofulous
Ooooh wow. This might be enough to get me to use Firefox to develop with. This
could be huge for its market share, a big part of the reason chrome was able
to become so popular was because of how good its devtools were (compared to
the competition at the time).

Firefox definitely managed to catch up but not before lots of devs switched to
chrome and stopped checking for compatibility with Firefox.

~~~
paulintrognon
Do you really think the web developpers that use advanced dev tools can make a
real difference in their market share? (real question)

~~~
bad_user
Developers in general are very influential.

Not only among our family and friends, but also because our choices create a
lock-in effect due to the nature of our work.

When you use Chrome day in and out, your work is going to be optimized for
Chrome and will work best on Chrome. This led to a Chrome-optimized web and
while Google isn't necessarily to blame, we're back to the days of " _works
best in IExplorer 6_ ".

Companies and products that attract developers will eventually attract regular
people as well. You could say that this is a chicken and egg problem,
developers following the users, but with few exceptions (like the iPhone) in
my experience thus far it's usually the developers that come first.

\---

It's worth mentioning that Chrome isn't popular only because of its technical
excellence, but also because of Google's incessant marketing and bundling. But
if we remember Microsoft and their declining browser market share, marketing
and shoving your products down people's throats isn't enough. The product,
especially if it's a _platform_ , has to not suck and to be used by developers
as well.

So yes, if other browsers like Firefox want to stay relevant and grow, a major
requirement is to provide excellent developer tools.

Kudos to Mozilla for understanding that.

~~~
scarface74
Developers and computer geeks have been overestimating their influence for
over a decade. If geeks were influential, the “year of the Linux desktop”
would have been years ago, no one would be on Facebook, and people wouldn’t
buy into Apple’s wall garden and people would care about “freedom”. Definitely
no one would have bought the iPod since it “had less space than the Nomad and
no wireless”. ([https://slashdot.org/story/01/10/23/1816257/apple-
releases-i...](https://slashdot.org/story/01/10/23/1816257/apple-releases-
ipod))

The consumerization of technology happened a long time ago.

~~~
bad_user
Not sure what you mean, but as an anecdote I quit using desktop Linux years
ago and whenever I go to developer conferences, the majority are on MacOS and
I think I see more people on Windows 10 than on Linux.

That people wouldn't buy into Apple stuff is a big assumption, because we did
do just that, for better or worse. Speaking of which, I see many more
successful commercial desktop apps for MacOS than for Windows or Linux
combined, even if Windows still has a much bigger market share. And this
happened since before Apple's App Store for MacOS became a thing.

I was also one of Facebook's early adopters, many of my programmer friends
were too. Being from Romania, let me tell you, the early adopters here were
all software developers ;-)

~~~
wolco
There might be some bias in there.

" see many more successful commercial desktop apps for MacOS than for Windows
or Linux combined"

Office profits by itself would crush all MacOS application sales.

Maybe it is easier for the single developer to create something profitable on
MacOS but that's because the bigger players have marketshare over windows in
the profitable niches.

~~~
scarface74
Office has always been available for the Mac. How many indy developers and
small shops outside of games really have been successful making software?

------
Roark66
They should've put this note at the very top of the page: "Mac OS only for
now!".

What is the point of promoting this to everyone at this stage?

~~~
jasonlaster11
Team member here. Firefox Replay is currently in user research phase while we
validate it.

Cross platform support will absolutely be a priority when Replay is on the
official roadmap.

Thanks for the feedback, firefox-replay.com is also a work in progress. We did
not plan an official release today.

We'll be sure to make the Mac OS limitation more clear.

Here is some more context on the mac specific functionality
([https://searchfox.org/mozilla-
central/source/toolkit/recordr...](https://searchfox.org/mozilla-
central/source/toolkit/recordreplay/ProcessRedirectDarwin.cpp#52-76)).

~~~
imvetri
What benefits it provides than record and playback using a screen recorder?

~~~
thw0rted
Based on the linked MDN page (from the current top-rated comment) it sounds
like the main point of this is to have a rewind-able debugger.

------
Etheryte
If this works well, it could eventually be a very big boon for Firefox in the
business world. Q&A can now send reproducible bug demos to development.
Technical clients can do the same. I wouldn't be surprised if someone built
tooling to map these recordings into automated tests either: expect the given
recorded workflow to not throw errors.

I can't quite remember when I had a bug where a tool like this would've been
useful, but I'm sure I would've been (and will be) very thankful for it.

~~~
sequoia
Oh yeah, wow. Having bug reports come with a replayable & inspectable
recording of the user's session would be an absolute game changer. We
approximate this now with telemetry tools that allow you to see what the user
was doing (sort of), but this would be 100x better.

~~~
tln
I wonder how often the bugs will be so deep that something like LogRocket
won't be enough.

------
devit
Why "Download Firefox Nightly for macOS"?

Is it not supported on Linux and Windows? Why?

~~~
dmos62
This blew me away a bit. Is MacOS this popular in the Web frontend crowd?

I always felt that the price/quality ratio was way off with MacOS, compared to
a good regular laptop. By good I mean top 10% ranked by price/quality. Even if
it wasn't, Apple's general hostility towards consumers is infuriating. Right-
to-repair is a banal example.

~~~
porker
> Is MacOS this popular in the Web frontend crowd?

Yes, and seemingly in the web backend crowd too (Ruby, PHP, Python but not as
much AFAICT).

If you go to a web conference and don't pull out a Mac, you do get comments
and/or questions (depending if you're running Windows or Linux).

At Python conferences I've seen fewer Macs and more of the good old ThinkPads
running Linux. My feeling is that community has a more "Computer sciencey"
taste in laptops, because they're not all web programmers.

~~~
isatty
> My feeling is that community has a more "Computer sciencey" taste in
> laptops, because they're not all web programmers.

Or maybe just because they _can_ be bothered to spend a few days setting up
their laptop just right and actively maintain it.

I'm a fairly advanced user but I can't be bothered to do so on a laptop and
would rather have a Mac to carry around and GNU/Linux on my desktop.

------
jasonlaster11
Thanks for the feedback!

Replay is in the user-research and validation phase and still quite
experimental.

firefox-replay.com is a work in progress. We're still sorting out the best way
to communicate record and replay debugging and the new use cases.

We'll share more on @firefoxDevTools when we have something to report.

~~~
sfttty
Great work! Some insights from FANG. Two more things are necessary to make
this a game changer: 1. JS level API to record RNR traces and upload them
along with error reports (this will be a new W3C standard). This will be a
compelling reason to include Firefox into the automation toolchain and at that
point compatibility with Firefox will be mandatory. 2. JS level virtualization
or sandboxing. Right now we have the iframe-level sandboxing but this
granularity is too coarse because modern web apps have become really big
(think of O365). We need a way to fragmentize the JS execution context into
smaller docker-like sandboxes and record RNR traces for them. Rationale: big
subcomponents should be isolated from each other and have separate traces. As
a side effect, this new VM API will enable us to do one cool trick.

------
ihuman
What's going on? I just see a block of text next to a static image.

"Replay is an early experiment. We'll let you know on @FirefoxDevTools when
it's ready for input."

~~~
Kaveren
I think they saw that it got a lot of attention on HN and weren't in a stage
with the product where they were ready for the corresponding feedback.

For anyone who missed what it was, it allows you to derterministically record
and replay your browsing for debugging purposes, and you can export these
recordings to others.

~~~
ihuman
I just looked it up on the internet archive and saw the old website. I think
they should have kept the old one, since the new website has almost no
information at all.

[https://web.archive.org/web/20191128111509/https://firefox-r...](https://web.archive.org/web/20191128111509/https://firefox-
replay.com/)

~~~
Narushia
That gives me “The Wayback Machine has not archived that URL.”

I also get the same for all the other snapshots, maybe Mozilla applied for a
takedown?

Edit: I found it on archive.is:
[http://archive.is/0ei35](http://archive.is/0ei35) Though it seems a bit
broken.

------
kevsim
The biggest benefit for me (I think) would be if the product/design people I
work with could find issues and send their recordings to me. Don't think I'll
be able to convince them to switch to FF though.

~~~
glassounds
[https://birdeatsbug.com](https://birdeatsbug.com) is great for that kind of
thing

~~~
jasonlaster11
Very cool. The product looks great!

~~~
makarov
Thanks a ton from the Bird team!

------
tenryuu
Regarding Mac OS: looks like, on Windows FF Developer Edition I can access
it's UI from creating a boolean in about:config named
devtools.recordreplay.enabled

A new option in settings will be added to enable a Toolbox Button named
"Enable WebReplay", but pressing that button will replace the entire tab
content with an about:blank

------
danShumway
My first thought is I'm mildly skeptical that this will end up being granular
enough or detailed enough to actually be useful in practice, but if it does,
it could be _very_ useful.

I'm pretty happy to see Firefox pushing its dev tools in this direction.
They've done a really great job with layout and styling tools, but their JS
dev tools have lagged behind Chrome's. So even if this particular effort
doesn't pan out for some reason, it's still very encouraging.

They're not just carbon-copying Chrome, and they're not just sitting back and
ignoring the dev tools; they're trying to push them forward in some
interesting ways.

------
inglor
Is there any way to make this work in automation? This could really help with
debugging failed e2e firefox tests.

------
mattfrommars
This is quiet cool! They did far better job then I would have imagined in
doing myself! Ha!

[Link to the editor]([https://github.com/abdusamed91/realtime-
codeeditor](https://github.com/abdusamed91/realtime-codeeditor))

I implemented it in my real time code editor coursework project where I made
use of [Ace Editor]([https://ace.c9.io/)'s](https://ace.c9.io/\)'s) CRDT. The
time machine slider does the job and looked remarkable when it ran.

------
brna
No Linux support :(

~~~
kreetx
Not Linux support _yet_ I hope :)

------
ga-vu
For those interested into how this works, look into Time-Travel Debugging and
the WebReplay API

------
saimiam
This didn't work for me.

1\. I installed the nightly build as told.

2\. Open nightly build

3\. Went to the "Save Recording" option

4\. The first two times, I got a [javascript error] saying I could not record.

5\. The remaining couple of times - after I open a "New Recording Tab",
whatever that is - I didn't see the javascript error but the website whose
clickthru I wanted to record using this tool didn't even load in that new
recording tab.

Just this morning I recorded a clickthru like caveman using Quicktime. Can't
wait for FF to iron out the kinks in this feature.

~~~
jasonlaster11
Hmm, join us in [http://devtools-html.slack.com/](http://devtools-
html.slack.com/) and we'd be happy to help you debug it.

If the tab crashed, you can get the report in about:crashes

~~~
nikivi
What do I do if I don't have mozilla or chromium email?

------
sdan
How is this different from recording in Chrome Web Dev tools?

To be clear, I use both Chrome and Firefox for development but just to the
surface level, so I'm probably missing the point here.

~~~
Vinnl
I'm not too familiar with "recording in the Chrome devtools", but this allows
you to actually step _back_ as well as forward in the debugger, e.g. for
inspecting the value a variable had when code executed before.

------
ManlyBread
This looks pretty good. Are there any other tools like this for different
platforms? I'd be especially interested in something like this for the .NET
ecosystem.

~~~
Vinnl
I'm not familiar with .NET, but I think both the Elm devtools and Redux
devtools can do something similar, although limited to their own features.

------
swsieber
Oh, oh, oh! This is so exciting!

I had built a poor mans version of this where I worked with puppeteer for
automated tests. It'd basically record the full dim any time it changed, along
with console logs, network request metadata, images and css and output it as a
test recording. You could then view that and walk through it in an Electron
app.

This'll blow it out of the water. I hope for e2e testing's sake that linux
support comes soon.

------
empressplay
Tangentially, our Apple II emulator [1] has a recording reverse-debugger,
should you want to do similar to debug 6502 code... ;) Developers of recent
Apple II games have been using it to resolve pesky bugs.

[1] [https://paleotronic.com/software/microm8/help/web-
debugger/](https://paleotronic.com/software/microm8/help/web-debugger/)

------
Blaiz0r
This looks great, it's good to see that Firefox is pushing new dev features,
instead of playing catch-up to Chrome.

Does Replay work on the Firefox Dev build?

~~~
y4mi
Seems to be a MacOS only feature.

------
asaddhamani
I would love to give Firefox a shot, but there's one thing I've had issues
with, when working with projects using things like webpack, when there's an
error, Chrome links me back to the original file and line, I never seem to be
able to do this in Firefox. Makes it so much harder to debug things. Am I
doing something wrong, or is there a way to fix this?

~~~
Vinnl
Not sure how long ago you tried, but in one of the recent Firefox versions,
they greatly improved the source map support - so it might just be that you
should give it another try.

~~~
asaddhamani
I've tried it with the latest versions (as of now), but it doesn't seem to
match up with how good Chrome is at it. I've tried both normal Firefox and the
developer version.

Why is this something Firefox seems to be struggling with? All the Blink based
browsers seem to be much better in this regard.

------
aedron
I am not primarily a web developer, but I guess I don't really see it.

I suppose 'rewind' would mostly be useful for Javascript applications? But in
Javascript you can already debug pretty well. It's been a while, but I suppose
Javascript debuggers can drop frames, like debugging other languages, so you
already have a kind of rewind?

Does anyone have a good example use case for this?

~~~
Vinnl
I'm not quite sure what "drop frames" means in this context, but a use case
would be stepping through the debugger, realising that the problem might be in
a piece of code that has already executed, and wanting to inspect the value of
a variable at that point in time.

Or even more mundane: accidentally hitting "Step over" twice in a row.

~~~
aedron
In most debuggers you can drop back up the stack to the code that called the
function you are currently in, and thus debug through the function call again.

Example: [https://stackoverflow.com/questions/2367816/when-using-
the-j...](https://stackoverflow.com/questions/2367816/when-using-the-java-
debugger-in-intellij-what-does-drop-frame-mean)

 _" Using the "Drop Frame" functionality you can "fall back" to a previous
stack frame, in a sense going back in time."_

~~~
nemetroid
That Stack Overflow answer is poorly worded though, looking at an outer stack
frame is really nothing like going back in time. Going back in time in the
Firefox Replay sense means reversing execution of the program, e.g. to find
the values of variables that have been mutated or gone out of scope.

~~~
aedron
But that's what drop frame does - it goes back to the state before your
current function call, including resetting variables. It does not revert
global state (like static variables) but it is essentially like reverting
execution 95% of the times I use it.

~~~
nemetroid
It doesn’t really ”go back”, it just shows a different stack frame, which is
part of the current state of the program.

------
Karupan
This will be an absolute game changer for web development. I am currently
working on a really simplified version of this, but as a chrome extension. We
deal with a lot of real time data and have been facing some timing issues
(network and user input) which is really hard to reproduce.

I’m going to give this a shot today!

------
foobaw
I wonder how this is positioned compared to Bird Eats Bug and
LogRocket/FullStory

~~~
makarov
Co-founder of Bird here. Firefox Replay seems to be focusing purely on
developers, while we see usage also from PMs, QA and even customer support. So
in the end developers can get more data from essentially anyone in the
company.

Over time we will be adding more tools for developers. It will be interesting
to see how Firefox will approach this compared to us.

------
jv22222
I've been working on a slightly related idea -
[https://speakhq.co](https://speakhq.co) \- I did submit as a Show HN, but
didn't get too much traction.

------
hyt7u
Just tried it out, and performance seems really bad at the moment, to the
point where I couldn't tell if it was working properly. Does anyone have any
suggestions of sites to try this on?

------
jrm2k6
It might just be me but enabling the option and clicking and the recording
button just attempt to reload the page and I get a blank page. Not sure what
is supposed to happen.

~~~
plorntus
Yeah happens to me too, guess either I'm missing an obvious button or it's
slightly broken on some machines (which is to be expected).

------
8bitsrule
Firefox is (mostly) a wonderful, free application. Linux is a wonderful,
stable, free desktop.

Strange days indeed. Just giving some thanks where it's due.

------
mimischi
So in its scope this somewhat similar to Cypress.io?

[https://www.cypress.io/](https://www.cypress.io/)

~~~
inglor
I don't use Cypress anymore as it didn't work for me but doesn't look like it.
This is for debugging rather than testing.

Also the timeline in Cypress didn't actually work too well for us.

------
Abishek_Muthian
Must admit, I've used screen recording during web development for some edge
cases; this might address those situations

------
deedree
What would apple have to do to let us have this on iOs? I would love to have a
choice of browser on my phone.

~~~
saagarjha
It’s not going to happen; even if you could run your own browser engine on iOS
this requires deep hooks into system calls and Mach messages which isn’t
really something that I would see Apple letting you do.

------
shepardrtc
Is it not appearing for anyone else? I downloaded it (for MacOS), and that
option does not exist.

~~~
shepardrtc
Wait, no, its fine. You have to go to the Web Developer tools, then settings,
and then turn it on via the check box.

------
meerita
I can't see it.

> An error occurred when connecting to firefox-replay.com.
> PR_CONNECT_RESET_ERROR

------
smnrchrds
Is there a replaying debugger for reverse-engineering dotNet programs?

------
markdog12
Really hope they can get this working with WebGL

------
softwarelimits
Can I add a little bit of randomness to this?

------
OrgNet
Is this a rebranded Firefox Focus?

------
kyriakos
Macos only for now

------
bogwog
Maybe once they figure out how to monetize the data

~~~
purple_ducks
Chrome's dev tools are so far beyond the competitions that this joke is a non-
starter.

When Chrome does add this capability(strange they haven't added it to date
given the prior art from years ago), I can see it being used by actual devs
inside Google and thus being actually useful.

Contrast that with Firefox dev tools which seem to fall behind the priority
list compared to new shiny flashy tech projects they concoct.

~~~
chinhodado
Don't know why you're downvoted but you're totally right. FF's dev tool is
still very far behind Chrome's. IIRC things like websocket inspection aren't
even in mainline FF yet.

If people want to see many examples of what Chrome's webtool can do and FF
can't, just take a look at this page "What's New In DevTools" for each Chrome
release.

[https://developers.google.com/web/updates/2019/10/devtools](https://developers.google.com/web/updates/2019/10/devtools)

~~~
dblohm7
> things like websocket inspection aren't even in mainline FF yet

Releasing with Firefox 71. [https://hacks.mozilla.org/2019/10/firefoxs-new-
websocket-ins...](https://hacks.mozilla.org/2019/10/firefoxs-new-websocket-
inspector/)

~~~
chinhodado
People have been asking for it for years though. IIRC Chrome has had it since
at least 2012.

------
wruza
As a former gnu/linux user, I see no point to have it on a desktop. Gnu is
happy to live under c:/MSYS2, and ‘linux’ part was never good at desktop-home
hardware anyway. These 1.77% are barely justified as an option, imo.

~~~
WanderPanda
After struggling with GPU drivers, again, the last couple of days, I could not
agree more!

~~~
adam12
I'm assuming these were the closed source proprietary GPU drivers.

------
sandGorgon
is this like Postman ?

~~~
lovasoa
No it is not. It is a browser feature that allows rewinding to a previous
state of a webpage. There is much more to that than recording and replaying
HTTP requests.

------
Shaaaaaaare
Looks interesting but too bad it only supports overpriced macs making it
useless

------
bdibs
Looks potentially really useful, but is it normal for them to create a whole
site just for one new feature?

~~~
archielc
If it is a killer feature, and that's a marketing move - why not. Looks like
that Firefox been working hard lately to change trends in browsers' market
share.

------
_bxg1
Very cool, but I'd much prefer they spend their time bringing Firefox's dev
tools up to par with Chrome's first. I've tried several times to switch to FF
completely, but every time I end up switching back on my work computer because
of the dev tools.

~~~
udfalkso
I recently switched back to FF after many years on chrome and find the dev
tools to be as good of not better this time around. Curious which tools in
particular you find worse? When was the last time you tried?

~~~
_bxg1
You know, as I'm going back and trying to come up with specific points, I'm
having a hard time.

Partly it's little usability things:

\- There was one time when an HTTP request was failing and I couldn't figure
out why, and in the Network tab Firefox wouldn't show any information about
it, even the request that went out (other than the URL), whereas Chrome not
only showed the headers, it surfaced that it was a 404.

\- There's no way to view all source files. You have to go to "Style Editor"
for stylesheets and "Debugger" for JS files. I'm not sure how to view the
other files that were loaded, outside of the Network tab.

\- I do enjoy how Chrome's inspector puts the box layout directly above the
computed styles, instead of in a separate tab.

Those all feel like nitpicks, though. It could just have more to do with me
not being used to it. Maybe I haven't given it enough of a chance and should
give it another try.

~~~
bogwog
FF's tools used to be pretty bad compared to Chrome's, and while my main
browser has always been FF I always keep Chrome around for development
purposes.

Lately though I haven't found myself needing to switch over to Chrome for
anything devtools related. This new replay feature makes FF even more
compelling (once it comes to Linux that is).

So if you haven't used FF for development recently, you should definitely give
it a try.

~~~
_bxg1
My last try was pretty recent, but it was also brief

------
inglor
We actually have something similar for this for tests at Testim
([https://testim.io](https://testim.io)) but only for tests with screenshots
and state.

Would people be interested in us open sourcing that part for regular
debugging? I have considered it but I didn't think people would be interested
in using this in a non-test case.

------
aphroz
While Microsoft is making great effort towards opening, it is sad to see
Firefox develop a feature working on Mac OS only. This is terrible because you
might argue that this is the same as a feature working on Windows only, but
Windows can run on different hardware manufacturer. This is like a double
closing. I am on Linux and I will uninstall Firefox as a repercussion hoping
it will have an impact. Too bad for the last hope for a chrome alternative.

~~~
senko
> Firefox develop a feature working on Mac OS only.

Looks to me like this is an experimental feature in Nightly. If it's highly
system-dependent I can't blame them for testing the feedback as early as
possible, before other systems are supported.

Question for Mozilla people here, if anyone sees it - is there a plan to bring
this feature across all systems in time for regular Firefox release?

~~~
IainIreland
Last I heard, WebReplay was not on an official roadmap (in the sense that we
do not yet have a target date for shipping it in release). That said, I'm
pretty sure that the macOS-only restriction is just because that's what the
primary developer is using, and it's a higher priority to get the system-
independent parts working first. If/when WebReplay is ready to ship, I can't
imagine a world where support isn't eventually added for Windows/Linux
(although it could be a phased rollout, like WebRender).

