Simon Willison's Weblog: Beats

.blend URL Viewer

2026-09-09T23:58:32+00:00

View Blender .blend files directly in your browser by pasting a URL to a CORS-accessible file or GitHub repository link. The viewer renders mesh geometry with materials, lighting, and optional saved camera positions from Blender 5.x files, and provides interactive orbit controls, wireframe mode, and model fitting capabilities.

llm 0.35

2026-09-07T23:54:54+00:00

llm 0.35

Access large language models from the command-line

Video compressor

2026-09-07T18:29:07+00:00

Video compressor

Compress videos in your browser using FFmpeg compiled to WebAssembly. Upload a video file to generate multiple encoded versions with different quality settings and output sizes, then compare and download the smallest file that meets your needs. All processing happens locally with no uploads to external servers.

Mercator ↔ Equal Earth

2026-09-07T16:24:16+00:00

Mercator ↔ Equal Earth

View an interactive animated map that morphs between Mercator and Equal Earth projections using a slider or play button. The visualization demonstrates how different map projections represent the world, with controls to blend between the two projection types and observe how they preserve different geographic properties.

There's No Limit to How Bad Code Can Get

2026-09-06T09:08:06+00:00

My comment on There's No Limit to How Bad Code Can Get — Lobste.rs.

[In reply to a comment about burning it down to start from scratch when technical debt becomes overwhelming]

In my experience it's so rare for that to work.

You announce the old thing is irrecoverably drowning in tech debt. You spin up a team to rewrite it from scratch. Work begins.

Meanwhile the old thing remains a moving target: it's running the core business, so changes are still necessary. The developers working on it know that it's going to be made obsolete by the new thing soon, so they don't have any incentive to go beyond the smallest effort possible to add the new features. Technical debt continues to mount.

Meanwhile, the team working on the new thing are ambitious and probably a little naive. They start out at a great pace - it's greenfield after all - but as time progresses it becomes apparent that nobody fully understands the behavior and scope of the thing they are replacing. If it was well documented and tested it wouldn't need to be replaced, after all...

After months (or even years) without delivering value, the pressure is on to "ship it", so the new system is launched to handle a subset of what the old system handled - or often for some new feature that was too hard to build with the now mostly unmaintained old system.

... so now you have TWO systems in production - the janky old system that nobody wants to touch, and a new system which handles just a few production features and is 80% inactive code that is meant to replace the old system, eventually.

If you're really lucky the company won't have lost patience with the new system and will allow that work to continue. The longer this all takes, and the longer the old system stays in production and stubbornly continues to work, the higher the risk that "priorities have changed" and the new system total replacement work is abandoned, leaving you with two systems where you used to have one.

The best article I've read about completing this process responsibly is Migrations: the sole scalable fix to tech debt by Will Larson.

If I run into a situation like this in the future, my strong recommendation will be to shore up the old system with as much automated testing as possible and then seeing if targeted refactors can get it to the desired shape. My hunch is that in many cases that will have a much higher chance of success than the siren call of a greenfield replacement.

Using Blender with coding agents on macOS

2026-09-05T15:51:09+00:00

Using Blender with coding agents on macOS

Modern frontier models have got *really good* at using Blender. I've been having a lot of fun trying this out recently - models can produce `.blend` files you can edit in Blender itself, and can also render images and even movies (by rendering a sequence of images and combining them with `ffmpeg`).

California Sea Lion

2026-09-05T03:24:30+00:00

California Sea Lion, in Monterey Bay National Marine Sanctuary, CA, US, CA

Osprey

2026-09-03T19:04:04+00:00

Osprey, in Pillar Point Harbor, CA, US

llm-openrouter 0.7.1

2026-09-02T20:23:26+00:00

llm-openrouter 0.7.1

LLM plugin for models hosted by OpenRouter

llm 0.34

2026-09-02T19:23:52+00:00

llm 0.34

Access large language models from the command-line

llm-anthropic 0.28

2026-09-02T17:59:32+00:00

llm-anthropic 0.28

LLM access to models by Anthropic, including the Claude series

llm-gemini 0.34

2026-09-02T16:39:38+00:00

llm-gemini 0.34

LLM plugin to access Google's Gemini family of models

GeoJSON Map Viewer

2026-09-01T18:05:45+00:00

GeoJSON Map Viewer

View and visualize GeoJSON data on an interactive OpenStreetMap with customizable styling options. Paste GeoJSON objects (Feature, FeatureCollection, or Geometry) into the editor, adjust fill color and opacity, and render the features directly on the map. Add multiple shapes with individual styling—each shape is numbered and can be removed, later shapes draw on top of earlier ones, and style changes apply live to the rendered map.

datasette-mcp 0.2

2026-09-01T15:30:12+00:00

datasette-mcp 0.2

Adds a /-/mcp MCP server to any Datasette instance

California Brown Pelican, House Sparrow

2026-08-30T23:59:38+00:00

California Brown Pelican, House Sparrow, in Monterey Bay National Marine Sanctuary, CA, US, CA