Pony

Last Week in Pony - April 5, 2026

Sean T. Allen — Sun, 05 Apr 2026 07:00:06 -0400

This week's theme song was pulled directly from the pool of "things to appeal to Sean musically." I give you "Apocalypse" by The Darts. Man, this one is great. Big week to go with it. ponyc 0.63.0 is out and you need to update. ponylang/hobby threw out its middleware and rebuilt around interceptors. And there's a whole repo of Claude Code skills for Pony. Three big things and I'm excited about every one of them. Let's go.

Last Week in Pony - March 29, 2026

Sean T. Allen — Sun, 29 Mar 2026 07:00:06 -0400

ponyc 0.62.1 is out and you need to update. There's a type system soundness hole in there, a Windows crash that we didn't fully nail last time, and a bunch more. Beyond ponyc, ponylang/hobby threw out its old handler model and rebuilt it around actors the way Pony wants you to build things. Big week. Let's crank up an oldie but a goodie, "Son of a Pig Farmer" by Krylls, and get into it.

Pony Gets an Embedded Linker

Sean T. Allen — Wed, 25 Mar 2026 15:00:00 -0400

As of ponylang/ponyc 0.61.1, the compiler carries its own linker. When you compile a Pony program on Linux, macOS, or Windows, ponyc no longer shells out to an external tool to produce your binary. It calls LLD directly, in-process, using the same LLVM infrastructure it already uses for code generation. Cross-compilation to Linux targets works the same way. The compiler is more self-contained than it's ever been, and cross-compilation just got a lot simpler.

Pony Gets a Template Engine

Sean T. Allen — Sun, 22 Mar 2026 15:00:00 -0400

If you've been following along, you know the story. Lori for networking. Stallion for HTTP. JSON back in the standard library. Pony's web development stack is coming together piece by piece. But a web stack that only speaks JSON is an API server with aspirations. At some point, someone is going to want an actual page.

ponylang/templates handles that.

Last Week in Pony - March 22, 2026

Sean T. Allen — Sun, 22 Mar 2026 07:00:06 -0400

ponyc 0.62.0 is out and you should update. There are bug fixes in there that matter, including one that was quietly breaking SSL hostname verification. Beyond that, there's a new multipart MIME parser, four new patterns, and pony-lsp landed in Helix. Let's get into it, but first, fire up this week's theme song: "Bloody Mary Morning" by Willie Nelson. Bob Wills might still be the king, but Willie is certainly in the royal court. Oh, and be prepared for lots of homework.

Persistent Data Structures for Concurrent Programs

Sean T. Allen — Wed, 18 Mar 2026 15:00:00 -0400

In my last post, I mentioned that the new json package uses persistent data structures under the hood. Every JsonObject is backed by a CHAMP Map. Every JsonArray is backed by a HAMT Vec. I glossed over why, and I want to fix that.

Pony Gets a New JSON Library

Sean T. Allen — Sun, 15 Mar 2026 15:00:00 -0400

For the first time in three years, Pony has a json package in its standard library. And this one has some tricks the old one never did.

Last Week in Pony - March 15, 2026

Sean T. Allen — Sun, 15 Mar 2026 07:00:06 -0400

What a great week in Pony! So much fun! Let's have two happy time theme songs for this week! We've got a packed ponyc release, BSDs are back in CI, json-ng landed in the standard library, and there's a brand new library for building LiveView UIs. This bunch is ripe for the picking.

Stallion: An HTTP Server Built Different

Sean T. Allen — Sun, 08 Mar 2026 14:00:00 -0500

Last week I wrote about lori and the architecture behind Pony's new networking stack. The short version: your actor is the connection, the protocol machinery is a class you own, no hidden internal actors between you and the socket. If you haven't read that post, go do that first. Everything here builds on it.

Stallion is an HTTP/1.1 server built on lori. Red has been running benchmarks comparing it against the old http_server package. Here's what he found, using 50 concurrent connections:

16-byte response body:

| Metric | http_server | stallion | |-------------|-------------|----------| | Requests/s | 441,570 | 710,416 | | 50% Latency | 106µs | 49µs | | 75% Latency | 125µs | 84µs | | 90% Latency | 151µs | 97µs | | 99% Latency | 1.89ms | 1.45ms | | Transfer/s | 34.11MB/s | 54.88MB/s|

100KB response body:

| Metric | http_server | stallion | |-------------|-------------|----------| | Requests/s | 160,052 | 192,069 | | 50% Latency | 254µs | 211µs | | 75% Latency | 375µs | 315µs | | 90% Latency | 0.97ms | 0.9ms | | 99% Latency | 3.07ms | 2.69ms | | Transfer/s | 15.27GB/s | 18.33GB/s|

A few caveats. These numbers only mean something relative to each other. The server and the wrk client were running on the same machine over localhost with keep-alive enabled, so don't go comparing them to your favorite web framework's benchmarks. And this is actually the best-case matchup for the old stack. The benchmark is dead simple. Turn off keep-alive and most of the difference disappears because socket open/close overhead dominates everything else.

Last Week in Pony - March 8, 2026

Sean T. Allen — Sun, 08 Mar 2026 07:00:06 -0400

This week's theme song is "Tennessee Quick Cash" by the incredible Charley Crockett. No secret meaning this time. I love Charley Crockett, I'm seeing him tonight, and I'm gifting you the love. A big week to go with it: a blog post about Pony's networking future, a massive ponylang/templates release, and the first release of ponylang/courier.

Pony Networking, Take Two

Sean T. Allen — Sun, 01 Mar 2026 14:00:00 -0500

Pony's standard library has a networking package. It works. If you're writing a simple TCP server or client, it'll get you there. But if you've ever tried to build something serious on top of it, something with real protocol logic, backpressure that you control, or TLS upgrades mid-connection, you know where the walls are.

I hit those walls years ago at Wallaroo. We ended up forking the standard library's TCP code and writing our own. That experience is where lori came from.

Last Week in Pony - March 1, 2026

Sean T. Allen — Sun, 01 Mar 2026 07:30:00 -0400

This week's theme song is Rawhide and it's so good, we are gracing you with 3 different versions. And this week calls for multiple versions because it has been a big week:

ponyc 0.61.0 shipped with a new \exhaustive\ annotation for match expressions
Three new libraries hit their first releases
Eight Pony patterns were published
The website got a top-to-bottom reorganization

Last Week in Pony - February 22, 2026

Sean T. Allen — Sun, 22 Feb 2026 07:30:00 -0400

Crank up this week's theme song — Horse Outside by the Rubberbandits — and settle in. Big week. We welcomed a new committer, shipped three brand-new libraries, and put out ten releases across five projects. There's also a persistent HashMap bug fix that enabled json-ng to drop its custom null type, three new Pony patterns, and a blog post about teaching Claude to write Pony.

Teaching Claude to Write Pony

Sean T. Allen — Tue, 17 Feb 2026 07:00:00 -0400

I'm not really sure how to tell the story of me teaching Claude to write Pony, so I'm just going to tell it and see how it goes.

A year ago, every LLM I tested on Pony produced the same thing: a weird Python/Pony hybrid that didn't compile and didn't understand Pony's semantics. I'd ask for a program that prompts you for your name and prints "Hello {name}." Simple stuff. They all failed miserably. So when I sat down two weeks ago to try again with Claude Code, my expectations were modest.

Last Week in Pony - February 15, 2026

Sean T. Allen — Sun, 15 Feb 2026 07:30:00 -0400

Crank up this week's theme song — George Jones doing "Hey Good Lookin'" — and settle in. Read fast, though. It's not a long song and this week's issue is longer than most. We've got thirteen releases across six projects. Major new versions of ponylang/ssl, ponylang/lori, and ponylang/ponyup, plus a preview of what's been piling up in ponylang/postgres.

Last Week in Pony - February 8, 2026

Sean T. Allen — Sun, 08 Feb 2026 07:30:00 -0400

Busy week on the release front. Ponyc 0.60.6 squashes several compiler bugs that were crashing instead of giving you error messages, Alpine support got bumped to 3.23, and seantallen-org/msgpack landed a big update with streaming support and compact encoding.

Last Week in Pony - February 1, 2026

Sean T. Allen — Sun, 01 Feb 2026 07:30:00 -0400

There's a new Pony available. It has a number of bug fixes and ships with a vastly improved language server. We suggest you upgrade soon.

Last Week in Pony - January 25, 2026

Sean T. Allen — Sun, 25 Jan 2026 11:30:00 -0400

There's a Pony release coming next weekend—get ready—there's lots of good stuff in it.

Last Week in Pony - January 18, 2026

Sean T. Allen — Sun, 18 Jan 2026 09:30:00 -0400

Not a lot of visible activity this week in Pony land, but there’s a lot going on and you can expect a few things to land in the not-so-distant future.

Last Week in Pony - January 11, 2026

Sean T. Allen — Sun, 11 Jan 2026 13:30:00 -0400

Sorry for the long delay between issues of Last Week in Pony. Life got in the way. I was down with the flu for several weeks. Then I fell out of rhythm and forgot a couple times that I write this thing up on Sundays.