· javascript
Rendering in batches with glimmer and Datastar
Anders Murphy recently wrote about [faster streaming HTML with batches and aggregates](https://andersmurphy.com/2026/09/29/faster-streaming-html-with-batches-and-aggregates.html).
When the server streams HTML to a page, it should collect the changes and render once for the whole batch. Similarly, it makes sense to avoid rendering the same thing twice for two different pages to avoid resending the data that the client already has.
I've been building glimmer and glimmer-datastar to do reactive server side rendering for jolt, and ran into similar problems. This post covers how both libraries have been reworked to facilitate batch processing, and how these changes are used in the newsroom app.
Glimmer is a Reagent-style library where state lives in ratoms which UI components subscribe to. The original target was native GUIs such as glimmer-gtk and glimmer-tui, but the reactive core is toolkit agnostic.
