Free-Astro

Free-Astro is an open-source collective that channels the work of professional and hobby astronomers into a single, cross-platform toolkit whose flagship product, Siril, has become the de-facto standard for serious astrophotography post-processing. Written in C with optional GPU acceleration, Siril addresses the complete workflow from raw DSLR or CCD frames to publication-ready pictures: calibration with darks, flats and bias; high-precision alignment and stacking of hundreds or thousands of subs; wavelet-based deconvolution, multiscale noise reduction and histogram stretching; photometric color calibration against star catalogues; and batch scripting for unattended overnight sessions. Although its core mission is deep-sky imaging, the same stack-and-enhance engine is frequently borrowed by microscopists, drone mappers and forensic photographers who need to squeeze signal out of noisy low-light sequences. Because the project is hosted on GitLab under GPL-3, a tight circle of contributors continually adds FITS and RAW format definitions, new comet and planetary stacking modes, and tight integration with ASTAP, PixInsight and ASCOM toolchains. Free-Astro’s software is available for free on get.nero.com, where downloads are delivered through trusted Windows package sources such as winget, always install the latest upstream build, and can be queued for batch installation alongside other astronomy or imaging utilities.