The new Rust-based DNS parser significantly reduces our security risk by mitigating an entire class of vulnerabilities in a risky area, while also laying the foundation for broader adoption of memory-safe code in other areas.
Every iOS app I've shipped over the last nine years started the same way: a Rails developer with a great web app, users who want it in the App Store, and weeks spent on Xcode, signing certificates, and Swift boilerplate that has nothing to do with the actual product.
One of my oldest open-source projects - Bob - has celebrated 15 a couple of months ago. Bob is a suite of implementations of the Scheme programming language in Python, including an interpreter, a compiler and a VM. Back then I was doing some hacking on CPython internals and was very curious about how CPython-like bytecode VMs work; Bob was an experiment to find out, by implementing one from scratch for R5RS Scheme.