A Forth-inspired language for writing websites

The article describes Forge, a stack-based programming language inspired by Forth, designed specifically for writing websites. It compiles to HTML on both the server and client side, enabling server-side rendering for crawlers and client-side rendering for a single-page application experience. The language supports features like persistent state through localStorage and an append-only server log, allowing for interactive elements such as like buttons.

A Forth-inspired language for writing websites I don't remember where the idea came from, but I decided that it would be cool if I could write websites using a stack-based language. Something like this: : h1 s -- "<h1 " emit . "</h1 " emit ; "Hello, World " h1 So I wrote Forge. I quickly built a library of word definitions that let me easily add microformats to the HTML: : post-content "Hello, world This is my first post with Forge " p ; : post-body h-entry-start "<p class='byline' " emit "2026-05-21T14:00:00Z" "May 21, 2026" dt-published " · by " emit "Beto" "/about" p-author "</p " emit h-entry-end "On building a tiny stack-based web language." p-summary "post-content" e-content "/hello-world" "permalink" u-url ; "Hello, world " "post-body" blog-post Each site is a collection of pages, a library of words, and a stylesheet: my-site ├── lib.forge ├── style.css └── pages ├── about.forge ├── hello.forge └── notes.forge A single binary runs the website: forge --log forge.log my-site/ The binary does a lot. It has a webassembly compiler that generates HTML from .forge files. When you visit a page the compiler runs on the backend, and you get the actual HTML in the source code, as well as the original .forge source. But when you navigate between pages, a service worker captures the network request to the page, say, /notes , fetches the source /notes.forge , and builds the HTML on the fly by running the compiler on the browser. So we have server-side rendering for crawlers and WebMentions, and client-side rendering for a SPA experience. I love the limitations of the language. You can persiste things to state, localStorage, or to an append-only log on the server. For example example, I can add a "like" button to posts like this: : like-button -- "❤" "do-like" on-click ; : do-like "1" "likes:demo" log-append ; : body "I liked this " p like-button ; When you click it, appends the value "1" to the topic "likes:demo" in the log. It's just JSONL one JSON document per line . Forms can submit to other .forge pages, and they simply put the contents in the stack for them. It's up to the target to use log-append to store in the backend. I like how weird it is. I might use it for my site, who knows? For now I'm just exploring some ideas.