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Credits, licences and trademarks

Helia's own licence

Helia is free software under the GNU General Public License, version 3 or (at your option) any later version, with the additional terms in ADDITIONAL-TERMS.md (GPLv3 section 7: the author attribution and the dedication are kept, and modified versions are marked as changed). The copyright is held by Laurence Horrocks-Barlow. The logo is not under the GPL: it is all rights reserved, see LOGO-LICENCE.md.

What is built into Helia

  • Rust libraries. Every library in the program is under a permissive licence (MIT, Apache-2.0, BSD, ISC, Zlib, Unicode-3.0, Boost-1.0 or similar). A few are offered under a choice of licences that includes a copyleft one; Helia uses them under the permissive option. The full list, with each licence text, is in THIRD-PARTY-LICENSES.txt in every release archive and package. The graphics and window layers are wgpu, egui and winit.
  • Fonts. IBM Plex Sans and IBM Plex Mono, copyright 2017 IBM Corp. with Reserved Font Name "Plex", under the SIL Open Font License 1.1 (the licence text is in the source tree, crates/helia-gui/assets/fonts/OFL-IBM-Plex.txt). egui's own default fonts are not included.
  • Data. Helia ships no star catalogue, deep-sky list or ephemeris file. The position of the Sun comes from published formulas (see References), and the limb-darkening coefficients are the published ones.
  • Test captures. The pictures and captures in the manual and the tests were made by the author with his own telescope and cameras.

Programs Helia runs but does not contain

  • ffmpeg reads MP4, MOV and compressed AVI files when it is installed. Helia starts it as a separate program and does not include, link or distribute it. It has its own licence, which depends on how it was built.
  • Vulkan, Metal and DirectX drivers come with your system. On Linux the optional Mesa software driver (lavapipe) is used only if you install it.

Credit

Helia stands on published work. References lists the papers and books for every method, and the doc comment of each module repeats them. The RegiStax-style wavelet controls follow the documentation and tutorials by Cor Berrevoets and others listed in Coming from RegiStax.

Trademarks

Other products are named in this manual only to say what they are or what Helia can read or do alongside them (for example "coming from RegiStax", "reads SharpCap files"). Helia is not affiliated with, endorsed by or sponsored by any of them. All product and company names are trademarks or registered trademarks of their owners, including:

AutoStakkert!, RegiStax, ImPPG, Siril, PixInsight, WinJUPOS, PIPP, SharpCap, FireCapture, AstroSurface, SER Player, PlanetarySystemStacker, SolHAT, JSol'Ex, ZWO and ASI, Seestar and ZWO ASIAIR, Celestron, Windows, DirectX, macOS, Metal, Apple, Linux, NVIDIA, AMD, Intel, Vulkan, FITS, Raspberry Pi.

Statements about other programs (their features, licence or platform) come from their public documentation at the time of the review in Research, are marked there with how far they were checked, and may be out of date. If a statement about your program is wrong, please say so through Feedback and it will be corrected.