Could someone in the know clarify for me what the difference is in aims of this new Browser ("Servo") and Firefox? The Servo landing page said its aims are
Servo project aims to achieve better parallelism,
security, modularity, and performance.
Parallelism: All current browsers are written to do layout in a single thread and the specs were written assuming this. When Servo started, whether you could write a parallel layout algorithm for the web was an open question. Servo has a multithreaded layout system that's faster than Firefox per-thread.
Security: The Rust programming language is memory safe. This prevents a large class of security vulnerabilities from happening. The number I saw was ~50% of the critical security vulnerabilities reported in Firefox in 2014 wouldn't be possible in Rust. It's also architected from the ground up to be multi-process sandboxed. I think there are other layers of defense but those are the two I know about.
Modularity: The pieces of Servo are in seperate repositories and the repos (crates) are actually used by the Rust community. Similarly, Servo pulls in crates from the broader community. This combined with the desire to port bits and pieces to Gecko makes the browser a lot more modular than you might expect. It's also designed for embedding and (I think) matches the CEF api so it should be usable wherever webkit/blink are but I haven't been keeping up with things there.
Performance: Parallel layout with a GPU-based scene graph [1] should result in a browser that's several times faster than anything currently available. The Servo team has been hesitant to really push benchmarks given the incomplete support but everything published is really promising.
Servo is a research project by Mozilla as a part of their Rust programming language. It gives them a "real world" app to build in Rust, so they don't end up doing ivory-tower designs that don't work well in real apps.
Despite the way some news articles might write about it, Mozilla does not intend this to be a new browser for regular people - It's an extension of their new language, and R&D.
Over time, Firefox may incorporate components written in Rust, potentially including parts from Servo, but AFAIK there is no timeline for that.
> Mozilla does not intend this to be a new browser for regular people - It's an extension of their new language, and R&D.
I disagree. While I'm not sure what the internal planning is, we are doing a bunch of things to move towards having a shippable Servo browser. If Servo was more of an experiment with no possibility of shipping there would be a whole host of features that we wouldn't even bother implementing it.
Servo's existence is also not to serve as a use case for Rust. If anything, it's the other way around, Mozilla was interested in Rust development because of Servo. However, over time Rust has gained a life of its own which is pretty awesome. (Yes, Servo does serve as a pretty good canary for Rust, but it's not the raison d'etre)
As far as Servo's future is concerned, there are a bunch of non-mutually-exclusive steps that can be taken going forward:
- Start moving components into Gecko (already being done) and write new ones (already being done): https://wiki.mozilla.org/Oxidation . Gecko can use Servo's URL parser, and wrote its own MP4 metadata parser. There's active work going on replacing Gecko's style/CSS system, and discussions about webrender. I've also seen some interest in dropping Rust into Spidermonkey.
- Expose a webview-like library (not being done yet, but there's interest)
- Release servo as its own browser, perhaps using browser.html (this is being coordinated at browser.html)
- Replace Gecko on Firefox for Android (this is not too hard, since the browser UI is simpler. Not being done yet)
- Replace Gecko in Firefox for Desktop (this is pretty hard -- there's no clear delineation between "Gecko" and "Firefox" and the UI uses things like XUL which I'd rather keep out of Servo). This is not being done yet.
Gecko is something of a pig. I find it hard to believe that Servo will be developed and then thrown away as purely a research exercise. I suspect Mozilla is hesitant to lay out a roadmap considering how young Rust is and how long rendering engines take to write, but it seems to me that its likely Servo will replace Gecko when its mature.
> "It's an extension of their new language, and R&D."
I'd suggest there's another set of aims that comes out of the work to make Servo easier to embed than Gecko, but the time isn't right to make the most of that yet.
