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KStars vs Cartes du Ciel (SkyChart): catalog facts
KStars	Cartes du Ciel (SkyChart)
Free Free and open source from the KDE community.	Free Free software under the GPL.
Windows, macOS, Linux	Windows, macOS, Linux
Sky simulation with up to 100 million stars, plus comets and asteroids Observation planner and calculation tools such as conjunction prediction	Uses many star and deep-sky catalogues Shows planets, asteroids and comets
The large feature set takes time to learn Some information and imagery features rely on internet resources	The number of settings can overwhelm casual stargazers Interface is functional rather than polished
Downloadable app	Downloadable app
Open source	Open source
License not stated	License: GPL
No account needed	No account needed
Not stated if it works offline	Works offline
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked October 2, 2026

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