August 10, 2026
CRT vs code: fight!
Tail-Call Interpreters in Rust – Jimmy Ostler
Rust coder chases speed gains, but readers rage harder at the eye-searing retro design
TLDR: Jimmy Ostler explored ways to make a tiny Rust command runner faster and more efficient, inspired by earlier work on similar ideas. But the biggest reaction was readers roasting the retro CRT website effect as unreadable, with one hero even posting a workaround so people could actually read the article.
A programmer set out to do something very inside-baseball: test different ways of making a tiny instruction runner in Rust, the coding language beloved by performance obsessives. The actual post is about squeezing more speed out of a mini virtual machine — basically a little engine that reads commands like “push this number” and “add these two.” But in true internet fashion, the comment section immediately found its own main character: the website’s faux-CRT styling, which several readers treated like a personal attack on their eyeballs.
The loudest reaction wasn’t “wow, clever benchmark,” it was “why is this page so unreadable?” One commenter flat-out cursed at the retro screen effect, while another arrived like the thread’s emergency IT support, calmly posting a step-by-step guide for disabling the dreaded text glow in browser tools. That turned the discussion into a classic tech-forum split screen: one side trying to talk about clever code tricks, the other desperately trying to survive the aesthetic choices long enough to read it.
There was still some genuine nerd joy in the chaos. Noel Welsh — whose earlier article inspired the experiment — popped in with a delighted “made my day,” then added a thoughtful idea about how one kind of interpreter can be transformed into another. So yes, there was brains here. But the vibe was unmistakable: cool experiment, cursed presentation. The meme of the moment? Readers basically saying the code may save stack space, but Firefox Reader Mode saved them.
Key Points
- •The article was motivated by a prior post on VM dispatch styles and applies those ideas to Rust implementations benchmarked against one another.
- •It explains tail-call interpretation as compiling recursive calls into jumps to avoid allocating new stack frames.
- •The article states that Rust can perform tail-call optimization under high optimization and mentions the unstable `explicit_tail_calls` feature.
- •A simple stack machine based on Noel’s Scala example is introduced with five instructions: `Lit`, `Add`, `Sub`, `Mul`, and `Div`.
- •The article presents a Rust switch-dispatch interpreter using a recursive `dispatch` function and `become` for tail calls, while noting that the sample’s `static mut` and `unsafe` usage is not recommended.