Hydra vs Walltone

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.

Walltone is a free GPL-3.0 wallpaper and theme manager for Linux. It handles static images, video wallpapers, and animated Wallpaper Engine content, with browsing and downloads from Pexels, Unsplash, Wallhaven, and Wallpaper Engine. Users can assign wallpapers per display, arrange monitor layouts, and adjust scaling. From wallpapers, Walltone generates light and dark Base16 and Material You color schemes; a color picker allows refinements and theme exports for other applications. Tag filters, search, sorting, Boolean filters, and a JavaScript-capable template engine support organization and customization. Video controls include mute and scaling. Wallpaper Engine controls include volume, FPS, audio, parallax, fullscreen pause, and texture clamping. Video or animated wallpapers can be captured as still images for login managers or GRUB. Online sources require API keys, including a Steam Web API key for Wallpaper Engine. Installation is listed through the Arch User Repository, a Nix flake, or source builds. Requirements include Linux, Node.js 18+, and playback and screenshot utilities.