Matt Keeter

It's a weird feeling to get an email which

- asks questions about one of your open-source projects
- references specific files in the repo
- those files are definitely not in the project

Are you from a parallel universe? Do they have any cool Fanta or Kit-Kat flavors over there?

Waymo spotted in Inman Square 👀

Got my first PR to a rust-lang repo merged 🎉

https://github.com/rust-lang/rust-analyzer/pull/22432

...is this dolphin telling me to commit crimes?

gonna go see the new adaptation of The Odyssey that everyone is talking about:

if only there was a high-throughput way to convert a large memory-unsafe codebase into a memory-safe language

https://github.com/v12-security/pocs/tree/main/fragnesia-5db89c99566fc

quick thoughts on the Bun rewrite:

My "This is clearly a legitimate WebGPU rendering crate, not malware" t-shirt is raising questions—

It's best practice for Rust crate docs to start with at least one research paper citation, which must be read before continuing.

Email Subject Lines With Threatening Auras

between Porchfest and opening day for the Union Square Farmer's Market, it's a big Saturday for aging millenials in Somerville

bytecode serialization: 0.3 ms
GPU compute kernel: 8 ms
waiting for the WebGPU polling thread: 100 ms
GPU-to-CPU buffer copy: 2ms

someone help me budget this, my framerate is dying
https://bugzilla.mozilla.org/show_bug.cgi?id=1870699

@whitequark@social.treehouse.systems I got nerd-sniped on bluesky to look at the actual wasm

The tailcall implementation does use return_branch_indirect as expected: https://gist.github.com/mkeeter/66df08eaf580f293c5f950baa43703b5

The traditional bytecode VM, on the user hand, uses br_table, at the end of a 250-deep stack of blocks (!): https://gist.github.com/mkeeter/66df08eaf580f293c5f950baa43703b5

It's kinda incredible: each opcode is its own block, and they each end with a break N instruction to break back out to the top level.

If – on this grey Sunday morning – you would like to read a dozen pages about using tail calls for fast interpreters, then I have Excellent News for you:

https://www.mattkeeter.com/blog/2026-04-05-tailcall/

raven-uxn now has an x86-64 assembly backend (yay!)

and it's about 2x faster (yay!!)

and the first draft was written by Claude (booo!)

and then I rewrote most of it, which made it even faster (yay!)

and introduced a memory corruption bug (booo?)

which Claude is better at debugging than I am (.......?)

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if you too have complicated feelings about our robot buddies, you may enjoy my writeup:

https://www.mattkeeter.com/blog/2026-03-15-uxn/

If this whole "computers" thing doesn't work out, I've got a bright future in aftermarket crib accessories!

hey chat is it good when a house on my block is held together by 2x4s?

doing some personal projects on an Oxide Computer instance

it's weird to think that when I type :w in nvim, I wrote the code which is actually persisting my data to physical disks!

with apologies to https://bsky.app/profile/getequipped.bsky.social/post/3mg3v5m3rku2p

tired: "Just trust the compiler, it's smarter than you are"
wired: "You are going to generate a fucking jump table, so help me god"

(this has made my GPU bytecode interpreter 1.5× faster)

I've been going for lots of walks around Cambridge, and it's nice to stop at a cafe for a snack while out and about – but it sucks that a drink + pastry is now $10-15.

If only there was some way to buy food in bulk and cache it at convenient locations around town in advance...

I've just announced my new (blazing-fast) kernel for implicit surfaces: https://mattkeeter.com/projects/fidget

It's got something for everyone: Cool graphs! Multithreaded WebAssembly! Terrible mesh topology! JIT compilers!

After three years, I'm excited to finally show it off to a wider audience 😎