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.

Spam bots flood busy Telegram groups with crypto scams and phishing links faster than human admins can delete them; TG-Spam watches every message and removes the junk before your members see it. Each message is scored by several checks at once: similarity to known spam samples, a stop-word dictionary, emoji and link counts, and a lookup against the Combot Anti-Spam database of known spammers. For borderline cases you can add OpenAI or Gemini as an extra judge, or write your own detection rules as Lua plugins that run inside the bot. The bot learns while you moderate: when admins approve a flagged message or ban a user it missed, the samples update, so the same trick fails next time. Members can report spam with a reply, repeat offenders accumulate warnings toward an automatic ban, and an admin chat gives your team one place to review borderline calls. Turn on the built-in server and the same engine answers spam checks over HTTP for your other tools, with a web UI to test messages, manage samples and dictionaries, and control the approved-user list. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

When Commento's original maintainer went quiet, Commento++ bundled the community's bug fixes and stalled merge requests into a batteries-included release of the beloved Go-based Disqus alternative - and kept building. The core promise is unchanged: an embeddable comments box that is orders of magnitude lighter and faster than Disqus, with no ads, tracking, or data sales - two lines of HTML and a PostgreSQL database. On top of Markdown comments, voting, Disqus import, OAuth login (Google, GitHub, Twitter) plus SSO, sticky comments, thread locking, and email notifications, the fork's additions are substantial: WebSocket-powered live comment updates with permalinks and highlight animations for new arrivals, guest commenting with a name, a cross-domain moderation dashboard for approving and deleting comments in one place, MathJax rendering support, wildcard domain matching, a reInit hook that makes single-page-application integration clean, and Perspective API spam scoring alongside the existing Akismet integration. Optional page-view logging graphs traffic on the dashboard, native SSL termination works without a proxy, and script-tag data attributes control fonts, CSS overrides, deleted-comment visibility, and polling-versus-WebSocket behavior.

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.

Any blog, documentation site, or static website can host a complete comment section by running its own Waline server, with Markdown, emoji, reactions, and moderation tools included. A visitor writes as a guest, registers an account, or signs in with GitHub, Twitter, Facebook, Weibo, or QQ, and a live preview shows the formatting before anything is posted. Comments accept tables, strikethrough, highlighted code blocks, TeX formulas, custom emoji packs, and Giphy GIF search. On submission, a sanitizer strips scripts and styles while Akismet, per-IP rate limits, keyword and IP block lists, duplicate detection, and reCAPTCHA or Turnstile screen for spam, and an optional review queue holds the comment back until a moderator approves it. The site owner then hears about it by email, WeChat, QQ, Telegram, PushPlus, Discord, or Lark, and the commenter receives reply emails. Once published, readers react with up to nine emoji and sort threads by latest, oldest, or hottest, while pageview and comment counters can appear anywhere on a site and recent-comment and top-commenter widgets fill sidebars. Moderators edit, approve, flag, or delete from the web admin panel, manage users and custom labels, and import earlier discussions from Disqus, Twikoo, Valine, Typecho, Artalk, Commento, or WordPress. Comments stay in your own database, and the widget offers a dark theme and ten languages. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-2.0 licensed.

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.

Comment sections at the Washington Post, the Wall Street Journal, and newsrooms across 30 countries run on Coral (also known as Talk) - the platform built by journalists' technologists, started under the Mozilla Foundation and now stewarded by Vox Media as an Apache-2.0 project serving 23 languages. Its founding premise is that online comments are broken and moderation is the fix. Moderators get a full queue system - reported comments, system-held pending comments, and configurable pre-moderation - backed by AI toxicity scoring that warns commenters before posting and holds high-scoring comments for review, Akismet spam detection, banned and suspect word lists, and automatic repeat-offender handling that pre-moderates users whose rejection rate crosses a threshold. Readers get features designed for healthier conversation: journalist badges in threads, muting of annoying voices, notifications, instant new-comment alerts, and timeouts rather than just bans. For publishers the economics are the point - no ads, no trackers, no hidden pixels anywhere in the code, full ownership of audience data, and GDPR compliance beyond requirements. Integration is one embedded script; SSO connects existing registration, and a GraphQL API supports customization and extension.

With over 14,000 GitHub stars and a growing global network of security deployments, CrowdSec turns every attack on any participating server into protection for the entire community. The security engine operates as a combined IDS/IPS and WAF, analyzing log sources from Nginx, Apache, SSH, WordPress, and over 50 other services to detect brute force attacks, port scans, web vulnerability exploitation, and credential stuffing in real time. When one server detects a new threat, the attacker's IP is shared through the community blocklist, proactively protecting thousands of other installations before the attacker can reach them. The built-in WAF powered by Coraza v3 inspects HTTP requests at the application layer, validates against OpenAPI schemas, and applies custom rules with flexible AND/OR condition mixing for precise threat detection. Bot detection serves challenge pages with client fingerprinting to distinguish legitimate traffic from automated scrapers and scanners. Remediation components block malicious IPs at multiple infrastructure layers including iptables, nftables, Nginx, HAProxy, Cloudflare, and AWS Security Groups through the detect-here-remedy-there architecture. The scenario-based detection system ships with default rules for common attack patterns and supports custom scenarios written in YAML with an expressive filter language. A centralized console provides real-time visualization of alerts, threat intelligence analysis, and management of multiple distributed security engines. GDPR compliant by design, all log analysis happens locally and raw logs never leave your infrastructure. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Leave a fake door unlocked and see who walks through: Krawl is a self-hosted honeypot that poses as a sloppy web server and records everything scanners and scrapers try. Fake WordPress, phpMyAdmin, and admin logins. Every attempt logged, every credential captured. A .env file leaking fake database strings, AWS keys, and Stripe secrets. SQL injection, XSS, path traversal, XXE, and command injection traps that answer with believable fake output. SQLMap gets a different database error on every request. Malicious crawlers wander an endless maze of random links. An optional tarpit adds delay and word salad that cost scrapers time, storage, and tokens. Optional AI-generated pages write a plausible decoy for any path an attacker requests. A hidden dashboard shows an attacker map, top IPs, captured credentials, and per-IP forensics. TLSH fuzzy hashing groups webshell variants into campaigns. A behavior score labels each IP attacker, bad crawler, good crawler, or regular user. Export bans as raw lists, iptables, or nftables rules, with guides for Fail2Ban, OPNsense, and RouterOS. A canary-token link in decoy pages emails you the IP and user agent of anyone who follows it. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

tirreno watches what accounts actually do inside your product, then surfaces the ones that look like account takeover, credential stuffing, fake signups, or insider abuse. Your backend reports events such as logins, registrations, page views, searches, email changes, and field edits through an SDK or one HTTP call, and a scheduled job turns them into per-user context: devices, IP addresses, sessions, and connected identities. Preset rules cover account takeover, credential stuffing, content spam, bot detection, multi-accounting, promo abuse, dormant accounts, API protection, and high-risk regions, and you can add rules of your own. Each rule adds to a risk score, and thresholds decide whether a user is flagged for manual review or suspended automatically. The review queue lists who needs a look, and the single user view shows behaviour patterns, risk scores, connected identities, and an activity timeline. A field audit trail records what changed and when, which supports compliance reviews, while the logbook lists every API request the instance received. Your application can ask a blacklist endpoint whether a user or IP should be blocked before it responds. An optional IP enrichment pack adds geolocation, ISP, and VPN or proxy detection. All event data stays on your own server. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

With 3,500+ GitHub stars and 100+ pre-built templates, OpnForm delivers a drag-and-drop form builder that handles everything from simple contact forms to multi-page surveys with conditional branching, calculations, and payment collection. The Laravel 11 API paired with a Nuxt 3 Vue frontend provides a responsive no-code editor supporting 20+ field types including text, date, file upload, signature capture, star ratings, phone numbers with country codes, and rich text. Conditional logic enables dynamic show/hide rules, required-field toggling, and calculated values that react to user input in real time. Submissions flow through configurable integrations — Slack notifications, Discord webhooks, Zapier connections to 5,000+ apps, Google Sheets sync, and custom webhook endpoints with full payload control. AI-powered form generation lets users describe a form in plain language and receive a ready-to-publish result. OIDC single sign-on with configurable state enforcement secures multi-user workspaces, while form-level passwords and CAPTCHA protection guard public-facing pages. Analytics dashboards track submission rates, completion times, and drop-off points. Forms embed via iframe on any website, Notion page, or custom domain with removable branding and custom CSS/JavaScript injection. The Docker Compose stack bundles the API, queue worker, scheduler, Nuxt client, PostgreSQL 16, Redis 7, and Nginx ingress proxy for a single-command deployment. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPLv3 licensed.