Maybe it's just me, but from time to time I try latest Servo build and it never survives more than few minutes of usage before crashing. Last time I did it was 3 days ago, I opened a website and it crashed with "RefCell already borrowed" in what seems to be a logger module. This always strikes me as weird because one of the selling points for Rust is memory and thread safety (quote from the website: "eliminate many classes of bugs at compile-time").