The erldns repository is an Erlang/OTP-based authoritative DNS server that processes DNS queries through a modular pipeline architecture. It loads zone data from JSON or standard zone files, provides DNSSEC validation and signing, and includes features like query throttling, EDNS0 processing, and an HTTP-based Admin API for runtime zone management and monitoring. The system is built using OTP supervision trees, with separate supervisors for listeners, pipeline workers, and zone loading. Key architectural strengths include a reusable pipeline pattern for extensible query processing, a worker pool for asynchronous operations, a segmented cache abstraction for high-concurrency scenarios, and admission control mechanisms using CoDel and Cubic algorithms. The Admin API follows a middleware pattern allowing custom extensions, and the zone loading subsystem supports pluggable codecs for custom record types. The codebase demonstrates strong engineering practices with comprehensive testing, dependency management, and observability via telemetry.
RSS-Bridge is a PHP web application that generates RSS, Atom, and JSON feeds for websites that do not natively provide them. The core architecture is a plugin framework: each of the 447 'bridges' in bridges/ extends BridgeAbstract (or FeedExpander/XPathAbstract/CssSelectorBridge) and implements collectData() to scrape HTML, consume JSON APIs, parse embedded JSON-LD/Next.js state, or expand existing feeds into a standardized item structure. A front controller (index.php) dispatches through a middleware pipeline (security, caching, basic/token auth, exception handling) to actions such as DisplayAction, FrontpageAction, ListAction, and FindfeedAction, then renders items via pluggable output formats (Atom, MRSS, JSON Feed, HTML, Plaintext, Sfeed). Both web and CLI request paths are supported, and the Docker deployment is production-ready with nginx + PHP-FPM and curl-impersonate for anti-bot evasion. The framework itself demonstrates solid engineering: a lightweight DI container, factory classes for bridge/format/cache discovery, a well-designed HTTP client layer with retry logic and CloudFlare detection, a standalone RSS 1.0/2.0/Atom/MediaRSS feed parser, systematic SEO/JSON-LD metadata extraction, and multiple cache backends (file, SQLite WAL, memcached, null) with TTL policies. PHPUnit tests cover feed parsing, format output snapshots, cache implementations, parameter validation, and BridgeImplementationTest enforces structural conventions across all bridges. The bridge base-class conventions (PARAMETERS arrays, contexts, detectParameters, throwClientException/throwServerException) are consistent and well-documented. The dominant weakness is inherent to the scraping domain: most bridges rely on brittle CSS selectors, undocumented APIs, or hardcoded endpoints that break as upstream sites change. Known issues visible in code include hardcoded API keys (Formula1, Giphy, Instructables, TwitterClient), deprecated/duplicate bridges (VkBridge states 'Does not work anymore'; Mozilla and Kernel BugTracker bridges defer to BugzillaBridge), logic bugs (Modrinth parameter key typo, GGDeals assignment-in-condition, Steam assignment-in-condition), a PHP 7.4 compatibility floor (EOL since 2022), and bundled Parsedown 1.7.4. The anti-bot arms race adds ongoing maintenance burden, and many low-traffic bridges appear effectively unmaintained. Overall, the core framework is a strong, extensible example of plugin-style feed generation architecture with genuinely reusable components; the bridge corpus is heterogeneous in quality, mixing well-crafted adapters with fragile scrapers. The project is actively maintained with recent commits, CI workflows, and a large contributor base.