Stellarium

What Stellarium does

Stellarium is a free, open-source planetarium software project initiated in 2006 by Fabien Chéreau and maintained by a distributed team of volunteer developers, loosely tied to Toulouse, France. The core application renders a realistic 3D night sky using Qt5/Qt6 with OpenGL 2.1/3.3 and GLSL shaders, drawing on default catalogs of 600,000+ stars and 80,000+ deep-sky objects, with extended Gaia DR3 catalogs providing 220+ million stars with full 6D astrometry. The product ships across Windows (x86_64 and ARM64), macOS, Linux, Android, and a browser-based Stellarium Web, and is augmented by roughly 25 plugins spanning telescope control (ASCOM, INDI, RTS2), ocular simulation, satellite tracking via CelesTrak, exoplanets, pulsars, quasars, meteors, scripting via an ECMAScript engine, and an HTTP Remote Control API. The software supports 40+ cultural sky traditions and 35+ calendar systems, positioning it as the de-facto reference tool for cultural astronomy research and a widely adopted teaching aid for astronomy educators and amateur stargazers.

Name

Stellarium

Website

https://stellarium.org

Company type

Private

Founded year

2006

Operating status

Operating

Headcount range

1–10 employees

Ownership category

akta.pro rank

Headquarters

HQ city

Toulouse

HQ country

France

HQ region

Europe

Offices1 record

Markets served

GTM type

B2C

Offering type

Software

Cost components

Personnel, Technology or R&D, Operations, Infrastructure, Others

Revenue model

1. Donations and Sponsorships: Free open source software funded entirely by donations from individuals and organizations. Major donors ($250+) include BairesDev, Litslink, and individual contributors listed on Open Collective. No direct revenue from software distribution.

Pricing tiers

Go-to-market motion1 record

Distribution channels5 records

Marketing channels5 records

Core offering

Stellarium develops and distributes a free, open-source 3D planetarium application for desktop (Windows, macOS, Linux) and web that renders a realistic sky for any time, date, and location using star catalogs (600,000+ default stars; 220M+ with Gaia DR3 extras), deep-sky object catalogs, atmospheric simulation, and 40+ cultural sky traditions. The software is extensible through plugins (telescope control, satellites, exoplanets, scripting, etc.) and is funded entirely via donations and sponsorships.

Product overview

Stellarium is a free open-source planetarium software suite consisting of a core desktop application and approximately 25+ plugin modules. The core Stellarium application provides a realistic 3D sky simulation with star catalogs, deep-sky objects, constellation visualization, and atmospheric effects across Windows, macOS, Linux, and Android. The product ecosystem includes Stellarium Web for browser-based access, with plugins organized into categories: object catalog plugins (Exoplanets, Pulsars, Quasars, Satellites, Novae, Supernovae), telescope interface plugins (Oculars, Telescope Control with ASCOM/INDI/RTS2 support), visualization plugins (Mosaic Camera, Scenery3d, Custom Nebula Textures), astronomical tools (AstroCalc suite, Calendars, Equation of Time, ArchaeoLines), interface plugins (Remote Control HTTP API, Remote Sync, TUI), and sky culture plugins (Sky Culture Maker). The scripting engine based on ECMAScript enables automation and external integration while the Remote Control Plugin exposes an HTTP-based API for programmatic control.

Differentiator

Problem solved

Functional benefit

Brands

• Stellarium Web: Web-based version of the planetarium software accessible through browsers
• Stellarium Mobile

Products and services

• Stellarium Free open-source desktop planetarium application that renders a realistic 3D sky as seen with the naked eye, binoculars, or telescope. Includes default catalogs of 600,000+ stars and 80,000+ deep-sky objects (extendable to 220M+ stars and 1M+ DSOs), 40+ constellation cultures, atmospheric and Milky Way rendering, telescope control, scripting, and dome projection. Available on Windows (x86_64, ARM64), macOS, and Linux.
• Stellarium Web Free browser-based version of the Stellarium planetarium that runs in modern web browsers without installation, providing access to the core sky-simulation experience for casual users and educational contexts.

Quantifiable outcome

• 600,000+ default stars, 220+ million with extra catalogs
• +2 more outcomes

Named customers6 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration11 records

Feature8 records

Partnerships

Two partnerships are on record, tiered minor and core.

• MicrosoftminorOthersMicrosoft donated a laptop for ARM64 development, enabling the Stellarium team to finalize Windows ARM64 platform support. This partnership facilitated ASCOM7 telescope support compatibility.
• Open CollectivecoreOthersFiscal host platform enabling donations and financial transparency for Stellarium's open source development. Handles incoming donations and sponsor management.

Scale indicators5 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Celestia: Free, open-source 3D space simulation software. Directly comparable to Stellarium as a community-developed, GPL-licensed astronomy visualization tool, though Celestia emphasizes deep-space travel over realistic ground-based sky rendering.
• KStars: KDE desktop planetarium offering similar star catalogs, telescope control (INDI), and sky simulation. Comparable as a free, open-source planetarium aimed at Linux/astronomy enthusiasts with strong community contributions.
• Cartes du Ciel: Free, open-source sky-charting planetarium with extensive catalogs and telescope control. Directly competes with Stellarium in the amateur-astronomy planning use case, particularly among advanced users.
• Space Engine: Procedural 3D universe simulator with both free and paid tiers. Overlaps with Stellarium in real-sky visualization but extends to procedural exoplanet and galaxy exploration, representing a commercialized version of Stellarium's scope.
• SkySafari: Commercial mobile planetarium app (Simulation Curriculum) for iOS/Android with extensive catalogs and telescope control. The most direct commercial competitor to Stellarium Mobile, demonstrating a proven monetization model for the same core use case.
• Star Walk: Vito Technology's commercial mobile planetarium app with AR sky overlay and subscription revenue. Comparable target audience (amateur astronomers and casual stargazers) but with a polished commercial UX and recurring revenue model.
• Starry Night / Simulation Curriculum: Long-standing commercial desktop planetarium software used widely in education and amateur astronomy. The classic paid alternative to Stellarium, with similar catalogs and telescope control, but priced per license.
• Microsoft WorldWide Telescope: Microsoft Research's (now open-sourced) virtual telescope for exploring terabytes of astronomical imagery. Comparable as a free, visually rich sky-survey and planetarium tool, backed by major institutional imagery datasets.

Emerging players

• Universe Sandbox: Commercial space-physics simulator allowing interactive gravitational and astronomical experimentation. Adjacent to Stellarium but focused on simulation/education rather than realistic sky rendering, popular in classrooms.
• Google Sky Map: Free mobile planetarium app for Android with point-and-look AR sky identification. Comparable amateur-astronomer use case at a much simpler feature scope, demonstrating the consumer-mobile funnel Stellarium could pursue.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key highlights6 records

Customer concentration

• GitHubgithub.com/Stellarium/stellarium
• Xx.com/StellariumDev

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Stellarium