mCaptcha
The CAPTCHA bargain - annoy your users and feed their behavior to Google - gets replaced with economics by mCaptcha. Instead of image puzzles, it uses SHA256 proof-of-work: every visitor's browser silently solves a small computational challenge (via a WebAssembly library) before submitting a form. Humans never notice the milliseconds; bots hammering your site must burn more compute sending requests than your server spends answering them, which makes attacks more expensive than defense - the property that also makes mCaptcha genuine DoS protection, not just bot filtering. Written in Rust, the system is fully automated: difficulty scales with traffic, so challenges stay trivial in normal conditions and harden under attack. The privacy and accessibility wins are structural rather than promised: no tracking, no profiling, no user-pattern data collection, and no visual puzzles that exclude users with visual or cognitive impairments - the design was published in Communications of the ACM. Rate limiting is IP-independent, so users behind NATs, VPNs, or Tor get the same experience instead of endless challenge loops, and proofs resist replay attacks, neutering captcha farms. Migration is deliberately easy: the API is compatible with reCAPTCHA and hCaptcha, making it a drop-in replacement. AGPL-licensed core with proprietary-friendly client libraries.
Muse
"A highly-opinionated midwestern self-hosted Discord music bot that doesn't suck," per its own README - Muse is built for servers the size of you, your friends, and your friends' friends. It exists because the big public music bots kept getting shut down or paywalled, and self-hosting yours means nobody can take it away. Written in TypeScript on discord.js, it joins voice channels and plays audio resolved from YouTube via yt-dlp, and given optional Spotify API credentials it auto-converts Spotify tracks, albums, artists, and entire playlists to playable equivalents. The playback details show real care: seeking within songs and videos, livestream support, local caching so repeated plays start instantly, volume normalization across tracks, and configurable volume controls including optional ducking that lowers music when people speak. SponsorBlock integration can skip non-music segments automatically. Users save favorite queries as reusable shortcuts, and one Muse instance serves multiple guilds simultaneously - one deployment for all your communities. Configuration is three environment variables (Discord token, YouTube API key, optional Spotify pair) and the personality is free: there is no vote-to-skip, because "this is anarchy, not a democracy," and the bot remains a loyal Green Bay Packers fan. MIT-licensed and easily extendable.