By the looks of it, Servo is a project that failed to deliver a new browser engine after years of work. If there were a chance that the project could be turned around to result in usable software, I'm sure Moz wouldn't have killed it. Is it worth the effort to pickup the project rather than starting from scratch? I don't know, and would appreciate if contributors share their opinion, or come up with a roadmap. By the reaction of some devs here on HN ("don't worry, Rust is safe; no really!") unfortunately I got the impression that the project was treated more as a showcase for Rust rather than a serious attempt at a new browser engine (please don't take it personally; I know this attitude from the "100% Javs" days and consider it a junior dev trait). Also, the "rise from ashes"/Phoenix metapher is no stranger to Mozilla, only that Moz picked the remains from Netscape; the effort to code a browser from scratch (in Java) had failed as well; it resulted in the Rhino JavaScript engine which is still heavily used.
Servo wasn't intended to build a full engine to replace Gecko, just to prove out components (Stylo, WebRender, etc) that could be integrated back into Gecko proper, built in a way that takes full advantage of Rusts strengths, and it's been pretty successful by that measure, IMO.
There was plenty more work to do (other commenters have mentioned a new layout engine), and I'm disappointed to see Mozilla abandoning such a core next-gen R&D project that has already brought substantial improvements to their main product.
Parts of Servo succeeded, like the webrender GPU stack and the CSS selector engine.
The parallel layout engine failed. It just kept running into corner cases that didn't handle parallel layout well. If you look in the layout_2020 folder in the source repository, you can see an in-progress pivot to a new approach that would hopefully have less problems, but now we'll never know.
This isn't a surprise. It was supposed to be a research project; if parts of it didn't fail, that would be a surprise.
By the looks of it, Servo is a project that failed to deliver a new browser engine after years of work. If there were a chance that the project could be turned around to result in usable software, I'm sure Moz wouldn't have killed it. Is it worth the effort to pickup the project rather than starting from scratch? I don't know, and would appreciate if contributors share their opinion, or come up with a roadmap. By the reaction of some devs here on HN ("don't worry, Rust is safe; no really!") unfortunately I got the impression that the project was treated more as a showcase for Rust rather than a serious attempt at a new browser engine (please don't take it personally; I know this attitude from the "100% Javs" days and consider it a junior dev trait). Also, the "rise from ashes"/Phoenix metapher is no stranger to Mozilla, only that Moz picked the remains from Netscape; the effort to code a browser from scratch (in Java) had failed as well; it resulted in the Rhino JavaScript engine which is still heavily used.