Part of the motivation of Rust and Servo is that Firefox in the long run is unmaintainable. It's many millions of lines of C++ code, any of which could corrupt

Part of the motivation of Rust and Servo is that Firefox in the long run is unmaintainable. It's many millions of lines of C++ code, any of which could corrupt memory or create a security vulnerability, and it's a very old codebase that has to deal with architectural decisions made decades ago when the web was very different. (Firefox was first released in 2002 as a fork of Mozilla, Mozilla was first released in 1998 as an open-source fork of Netscape Navigator/Communicator, and Netscape Navigator was released in 1994.) Mozilla had the option of either remaining in long-term software maintenance mode and falling behind or doing something to move forward the state of the art in browser design and security. Sometimes the seemingly-risky choice is actually the safer option; I hope it works out.