RhoMD Docs Download

License & Commercial

Rho's three-layer license architecture — spec public / library noncommercial / app & cloud closed-source — and how to inquire about commercial licensing.

Three-layer architecture

┌────────────────────────────────────────────────────┐
│  Layer 1: Rho Format Spec                          │
│  License: CC BY 4.0                                │
│  Anyone can read / implement / republish — only attribution required │
└────────────────────────────────────────────────────┘
                        │ defines
                        ▼
┌────────────────────────────────────────────────────┐
│  Layer 2: @rho/md library (npm)                    │
│  License: PolyForm Noncommercial 1.0               │
│  Personal / academic / non-profit free · Commercial paid │
└────────────────────────────────────────────────────┘
                        │ powers
                        ▼
┌────────────────────────────────────────────────────┐
│  Layer 3: Rho desktop app + cloud.rho.md           │
│  License: Closed-source / personal-free (app) · Paid SaaS (cloud) │
└────────────────────────────────────────────────────┘

Each layer has its own license, no upward enforcement.

Layer 1: Rho Format Spec — CC BY 4.0 ✅ Fully free

What you can do

  • ✅ Read / cite / translate the spec
  • ✅ Implement your own Rho reader (any language, any license — your choice)
  • ✅ Commercial products integrating it (the implementation is yours; you just need to attribute the spec)
  • ✅ Fork / modify the spec for your own use (modified versions must be declared)

What you must do

  • Keep attribution in your reader's docs / about page: "Implements Rho format spec by scos-lab" or similar

Full license

Creative Commons Attribution 4.0 International (CC BY 4.0)

Layer 2: @rho/md library — PolyForm Noncommercial 1.0 🟡 Noncommercial

✅ Free use

  • Personal projects (personal blog, portfolio, personal tools)
  • Academic research (university lab, paper demos, teaching materials)
  • Non-profit organizations (charities, educational institutions, governments)
  • Evaluation / trial (30-90 day internal company trial)
  • Open-source hobby projects (no money, no commercial purpose)

❌ Requires payment

  • For-profit company any use — including:
    • Internal tooling (your SaaS dashboard using Rho)
    • Customer-facing products
    • Integration into your commercial service

How to pay

→ See Commercial licensing

→ Contact: [email protected]

Full license

→ See Full license text or PolyForm site

Layer 3: Rho desktop app + cloud.rho.md — Closed-source

Rho desktop app

  • Personal use free — download the binary, use it
  • Commercial / team deployment: $X/seat/month (pricing TBD)
  • Enterprise SSO + SLA: contact sales

cloud.rho.md (SaaS)

  • Free tier: personal use, public sharing
  • Pro tier: private sharing, custom short links, watermark removal (pricing TBD)
  • Team tier: team workspaces, SSO, audit log (pricing TBD)
  • Enterprise: custom deployment, SLA, compliance

See Cloud Roadmap (not in public docs; internal reference).

Decision matrix: which layer / do you owe?

What you do What you use Pay?
Personal blog with interact blocks @rho/md integration ❌ Free
Personal desktop reading .md Rho app ❌ Free
Company internal wiki with interacts @rho/md integration ✅ Commercial license
Company customer-facing product embedding Rho @rho/md integration ✅ Commercial license
University course teaching Rho spec + @rho/md ❌ Free (academic)
Online education platform using Rho (paid courses) @rho/md ✅ Commercial license
Self-implement reader without @rho/md spec only ❌ Fully free (CC BY)
Public sharing of docs cloud.rho.md free tier ❌ Free
Company internal sharing / private cloud.rho.md Pro/Team ✅ Subscription

Not sure? See Free use FAQ or email [email protected].

Why this design

  • Spec public — push markdown standardization evolution; commercial product integration needs no permission
  • Library noncommercial — a primary monetization path; personal / academic / non-profit stay free for outreach
  • App / Cloud closed-source — primary monetization paths; users get a polished experience

Aligned with mainstream dev-tool patterns: spec free + lib noncommercial + product paid.

Similar precedents:

  • HTML/CSS spec free → Chrome closed parts / WebKit partial license / various closed products
  • PDF spec ISO 32000 free → Adobe Reader closed-source
  • Bluetooth spec free → various closed implementations

See also