Show HN: Bento - An entire PowerPoint in one HTML file (edit+view+data+collab)
Points and comments are a snapshot, not live.
Bento packs an entire presentation editor with collaboration into a single HTML file.
Bento is a single-file HTML presentation app that stores slide data as JSON near the top of the file. The app itself is a base64 blob decompressed in the browser via DecompressionStream, keeping the file small and self-contained. It uses the File System Access API for saving changes back to the same file. Collaboration is enabled via ECDSA-signed updates relayed through Cloudflare Durable Objects, which only see encrypted data. The creator started from reveal.js and GSAP/Flip but reimplemented both when integrating echarts caused issues. Auto-update checks for signed manifests and rewrites the file with new versions.
What commenters are saying
Commenters praised the single-file approach as a refreshing alternative to subscription-based software, with several noting parallels to TiddlyWiki and HyperCard. The creator answered technical questions about the architecture: the file stores JSON slide data alongside a compressed base64 app blob, uses Cloudflare Durable Objects for encrypted collaboration relay, and supports auto-update via signed manifests. One commenter reported a pinch-zoom bug on mobile Safari. The creator acknowledged the loss of reveal.js's vertical slides feature and said they would investigate incorporating it. A suggestion to use Nostr relays instead of Cloudflare was noted positively.