Colophon
Frameworks
- Python 3 — language runtime
- Django 6 — web framework
- HTMX 2.0.4 — HTML-over-the-wire interactivity
- Tailwind CSS 4 — utility-first CSS framework
- django-htmx — Django integration for HTMX
- WhiteNoise — static file serving
Libraries
- django-tasks — background task queue for outbound email
- django-waffle — feature flags
- django-csp-plus — Content-Security-Policy headers and violation reports
- py_webauthn — passkey (WebAuthn) registration and sign-in
- pywebpush — Web Push notification delivery
- Shapely — region boundary geometry
Data
- WSL Institute for Snow and Avalanche Research SLF — avalanche bulletins for Switzerland, licensed under CC BY 4.0
- Avalanche.report (ALBINA / EUREGIO) — avalanche bulletins for Tyrol, South Tyrol, and Trentino, licensed under CC BY 4.0
- Météo-France — avalanche bulletins (BRA) for the French mountain ranges, used under the Météo-France open-data licence
- Open-Meteo — elevation data
- European Avalanche Warning Services (EAWS) — region boundaries and danger/problem iconography
- GeoLite2 by MaxMind — offline database used to derive an approximate location from a request's IP address, licensed under CC BY-SA 4.0
Basemap
- MapLibre GL JS 4.7.1 — open-source map renderer
- OpenFreeMap — Liberty vector tiles (the default basemap in the picker, and the production default)
- © OpenStreetMap contributors — the map data behind the Liberty tiles, licensed under the Open Database Licence (ODbL)
- swisstopo — Winter vector tile style, covering Switzerland
- IGN — Plan IGN vector tile style, covering France
- basemap.at — vector tile style, covering Austria
- swisstopo — Slope classes over 30° — the map's slope-angle overlay, classified as the SLF recommends (30–35°, 35–40°, 40–45°, 45–50°, over 50°) and derived from a combined 10 m elevation model: swissALTI3D, RGE ALTI, TINITALY/01, DGM10, DGM1 and EU-DEM
Icons
- Yr weather icons by the Norwegian Meteorological Institute and NRK — weather condition icons, licensed under the MIT licence
- Meteocons by Bas Milius — the sunrise and sunset icons, licensed under the MIT licence
- EAWS — avalanche problem and danger-level SVGs, licensed under CC BY 4.0
Fonts
- DM Sans and DM Mono — licensed under the SIL Open Font Licence 1.1
- Resend — transactional email delivery
Analytics
- PostHog — anonymous product analytics. Events are sent from our servers, not your browser; what is collected is described in the privacy policy
Hosting
- Render — web application hosting and cron jobs