EarthDesk vs Hydra

EarthDesk turns a computer desktop into an updating view of Earth from space, with near-real-time clouds, sun and moon depictions, and city lighting. It offers 12 map projections, including Mercator, Azimuthal, Equirectangular, and a globe with optional starfield. Maps can be centered using latitude and longitude, relative to the sun or moon, or on one of 10,000 locations; a data subscription adds other centering choices. On multiple displays, it can show a different map on each screen or span one map across them. Standard cloud imagery is global, 2-megapixel, and refreshed every six hours. The data subscription adds geo-located, parallax-corrected imagery from 23 satellites at 32-megapixel detail, refreshed every three hours, plus earthquake, tropical storm, and International Space Station information. The maker offers a free Mac or Windows trial before purchase. A single-user license starts at 24.99 USD once and covers two Mac or Windows computers. An upgrade costs 12.99 USD once and requires a previous license key; the data subscription costs $14.99 a year. Minimums are macOS 10.14, Windows 7, or tvOS 13.2.

Hydra is a continuous integration service for projects based on Nix. It checks out project source periodically or continuously, builds it, runs tests, and produces reports. Work is organized into jobsets whose inputs can trigger builds when they change; jobsets can also depend on one another. Flake jobsets are supported when their outputs expose a hydraJobs attribute set. Jobs can produce packages, ISO images, or tarballs, and jobset inputs can use Git checkout sources. Hydra also provides a JSON API. It is aimed at Nix and NixOS package developers, not people who only need to use NixOS. Hydra is open source under GPL-3.0 and listed at free. It is self-hosted, with no hosted option listed, and running it is currently supported only on NixOS; the repository recommends the NixOS module for production. Flake evaluation is restricted from accessing files outside the Nix store. Some state is stored in the database, so backups are needed, and the wiki reports that hydra-queue-runner can sometimes leave queued builds unscheduled.