A community-driven project that offers a progressive web app (PWA) that works offline. It is not as powerful as Sirius for professional forecasting, but it handles Natal charts beautifully.
Sirius 4.0 is the latest stable release (circa 2020-2024). It incorporates Pluto in Aquarius and trans-Saturnian objects. No legitimate free download of 4.0 exists outside the 30-day trial. Sirius Astrology Software Free Download