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Cartes du Ciel (SkyChart) vs WorldWide Telescope: catalog facts
Cartes du Ciel (SkyChart)	WorldWide Telescope
Free Free software under the GPL.	Free Free and open source.
Windows, macOS, Linux	Web
Uses many star and deep-sky catalogues Shows planets, asteroids and comets	Large collection of sky imagery in the browser Guided tours with narration and slides
The number of settings can overwhelm casual stargazers Interface is functional rather than polished	Needs a fast internet connection Interface can feel dense for newcomers
Downloadable app	Web application
Open source	Open source
License: GPL	License not stated
No account needed	Not stated if an account is needed
Works offline	Needs internet
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.