Firefox 58 will be faster at compiling WebAssembly code coming in from the network thanks to 'streaming compilation' -- which allows code to be compiled and downloaded in parallel -- and a faster two-tiered compiler.
In the past, web performance was constrained by the network, Clark said, but the new bottleneck is the CPU and the main thread. Firefox 58 takes the burden off the main thread and makes better use of a CPU's time.
"If you start compiling the code earlier, you'll finish compiling it earlier. That's what streaming compilation does... makes it possible to start compiling the .wasm file as soon as possible. When you download a file, it doesn't come down in one piece. Instead, it comes down in a series of packets."
Meanwhile, Firefox 58's two-tiered compiler aims to get around the compiling time trade-off between optimizing code while compiling or compiling non-optimized code.
"We can have the best of both of these worlds. If we use two compilers, we can have one that compiles quickly without too many optimizations, and another that compiles the code more slowly but creates more optimized code," writes Clark.
Firefox 58 is currently in beta and scheduled for release on January 23, and Mozilla hopes the latest speedups will tempt more former users to give Firefox another chance.
The upcoming Firefox 59 will help you stop sites from asking for permission to send you notifications and know your location, but you can stop these right now in the current build of Firefox with a little digging.