Show HN: Tenno – Markdown and JavaScript = a hybrid of Word and Excel

Original Article ↗ Hacker News Discussion ↗

A new web-based tool called Tenno blends Markdown with live JavaScript “cells” to create documents that behave like lightweight, executable spreadsheets, aiming to make data analysis and visualization more approachable than traditional tools like Excel or Jupyter. Commenters see strong potential for literate programming, sharing interactive reports with non-technical users, and local/offline use, but point out gaps such as robust table support, better error handling, mobile-friendly and WYSIWYG editing, and clearer positioning versus existing tools like Org mode, Observable, and Evidence.dev. Many view Tenno less as a direct Excel replacement and more as an interesting direction for extending Markdown into a general-purpose, computable document format.

Concept & Positioning

  • Tenno extends Markdown with inline JavaScript “cells” to mix narrative and computation, aiming to feel like a hybrid of Word and Excel.
  • Many see it as part of the “literate programming” / executable docs lineage, similar in spirit to Jupyter, Observable, Org mode tables, MDX, and other notebook/wikilike tools.
  • Some find the DSL intuitive and ergonomic; others would prefer plain TypeScript/Python or see it as “just” a templating language with variables.

Local vs Web, Storage & Security

  • Several users want a fully local, desktop-style app with files on disk, not a pure web app.
  • The author notes it already runs fully in the browser after first load and has been successfully packaged as a small macOS app; local-first packaging is considered feasible.
  • Corporate security flagged the site as “grayware,” possibly because it executes arbitrary JS via eval().

Data, Tables & Integrations

  • Strong demand for serious table support: large tabular data, cell formulas, derived tables, and Excel-like operations (sums, averages, referencing other tables).
  • Requests include:
    • Integration with Google Sheets (especially public sheets) and/or local tables.
    • Ability to query local SQLite/DuckDB via SQL.
    • Bignum and complex-number support.
  • Some argue calling it an “Excel hybrid” is premature without proper cell expressions and robust tabular tools.

UX, Error Handling & Mobile

  • Users like inline editable controls and simple charting; current chart DSL is seen as under-documented.
  • Error handling is fragile; malformed chart commands or type mismatches can crash or glitch the UI, prompting calls for better validation and error boundaries.
  • Editable fields sometimes lose focus on each keystroke, making interaction frustrating.
  • Mobile experience is poor: non-responsive layout and split-pane make it “unusable” on phones; suggestions include vertical split, mode toggles, or read-only default on mobile.

Naming, Audience & Vision

  • Name “Tenno” overlaps with a game faction, a lake, and a Japanese word; some foresee SEO friction.
  • Debate on target audience: programmers vs power users vs general spreadsheet users. Many believe it should lean into its niche (executable Markdown docs) rather than trying to replace Excel outright.