Artalk embeds a full commenting system into any webpage with three lines of JavaScript, packing multi-site management, social login, spam filtering, and Markdown rendering into a client that weighs roughly 40KB. One server instance manages comments for unlimited websites with complete data isolation between sites, eliminating the need for separate deployments per project. The framework-agnostic Vanilla JS client renders a complete comment interface with Markdown support, LaTeX mathematical formula rendering, image uploads, emoji packs compatible with OwO format, and automatic dark mode detection. An integrated admin dashboard accessible through the comment box provides comment moderation queues, IP banning, comment pinning, page-level statistics, and content management without direct database access. Social login authenticates commenters through GitHub, Google, Twitter, Discord, and additional OAuth providers, while captcha protection spans four backends: image captcha, Cloudflare Turnstile, Google reCAPTCHA, and hCaptcha. Spam filtering layers include Akismet integration, keyword block lists, and cloud moderation services that catch unwanted content before publication. Email notifications support SMTP, Aliyun DM, and Sendmail transports with customizable templates, and multi-channel push notifications extend to Telegram, Bark, and other messaging platforms. The OpenAPI-documented HTTP API enables programmatic comment management. Database flexibility covers SQLite, MySQL, PostgreSQL, and SQL Server. A plugin marketplace offers community extensions for custom behavior. Continuously maintained for over 8 years. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Comments for small sites without Disqus's baggage: Cusdis is a lightweight, privacy-first, open-source comment system for embedding under blog posts and articles. The embedded JavaScript SDK is about 5 KB gzipped (Disqus is roughly 24 KB), sets no cookies, runs no tracking, and does not require readers to create an account or sign in before commenting. Integration is two lines: a container div with your app ID and an async script tag, with ready-made adapters for common frameworks and static site generators. Moderation is approval-based - new comments stay hidden until you approve them from the dashboard, and email notifications include a Quick Approve link that approves or replies to a comment from your phone without logging in. A webhook fires on every new comment for integrations like Telegram notifications. The widget ships with built-in i18n and dark mode. The stack is TypeScript and Next.js with a Prisma data layer, deployable via Docker with PostgreSQL. Deliberately minimalist: no ads, no reader profiling, and your comment data lives in your own database.

Named from the German "Ich schrei sonst" - roughly "or I'll scream" - Isso is a lightweight Python/JavaScript commenting server, a drop-in Disqus replacement for people who noticed what Disqus does to reader privacy and page load times. The design premise is printed right in the docs: comments are not Big Data. So the backend is a single SQLite file rather than a database cluster, and the entire client is one embeddable JavaScript file - 65 kB, 20 kB gzipped - that you drop into any static site, blog, or CMS. Commenters write in Markdown, need no account, and can edit or delete their own comments within a configurable window (15 minutes by default). Spam control comes from an optional moderation queue: held comments stay invisible until you activate them via an admin interface or email notification links. Migration is a first-class feature, with importers for Disqus and WordPress exports, so years of existing threads move over intact. Because everything is server-rendered from your own instance, no third party tracks your readers, and real-world switchers report smaller pages and faster loads than the Disqus embed. MIT-licensed, running since 2012.