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.
Seriously, the feature is still in beta - one platform had to be first, and it happened to be OS X. Linux and Windows support is on the roadmap: https://news.ycombinator.com/item?id=21656114
The feature needs OS-specific work, so one platform had to be first, and for whatever reason MacOS was chosen. It's more useful to have it working reasonably well on one platform, to get feedback on the feature, than to have it in a bad state on all platforms.
So, no need to over-react. If Mozilla decides it's worth shipping, they'll port it to other plaforms.
All that looks to have happened is the developers of this single feature that is in the nightly build are using Macs. It is wholly reasonable for them to only support one platform at this point. If it is a good feature they, or other devs attracted by this preview will port it.
I would be worried about this if the plan was for it to only support MacOS on mainline Firefox. This is Nightly, two release cycles ahead of regular Firefox, and support will be coming to other platforms: "porting it to other POSIX systems (Linux, Android) will be easier than Windows, due to the overlap with macOS" (https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We...)
This comment doesn't even make sense, as with a little digging you could've found this[0] information yourself:
"Windows port work is underway, but is not yet working. The difficulties are in figuring out the set of system library APIs to intercept, in getting the memory management and dirty memory parts of the rewind infrastructure to work, and in handling the different graphics and IPC pathways on different platforms."
In fact, their documentation makes a specific call-out to TTT (Time-Travel Debugging) on Windows; so, I suspect that this is the API that they would like to use but are unable to do so at present (presumably because many of the features are still lacking in the API, which Microsoft could - and most probably would - enable).
> 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?
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).
