In-app, website, link, and email surveys feed one open-source experience management platform: Formbricks. Its distinguishing strength is targeted in-app research: a JavaScript SDK triggers surveys on user events and attributes, with segmentation rules like "power users who have not seen a survey in 10 days," so questions reach the right cohort at the right moment instead of a mass email blast. The no-code editor offers 20+ question types including NPS, CSAT, CES, matrix, ranking, and file upload, with skip logic, conditional branching, best-practice templates, and full brand theming. Responses feed built-in analytics with summaries and CSV/JSON export, and integrations push data to Slack, Notion, Google Sheets, Airtable, Zapier, and n8n, with webhooks and an open API on every tier. Because self-hosted surveys load from your own domain rather than a blacklisted third-party script host, ad blockers do not suppress them - in-app surveys reach users that Hotjar-style tools silently miss, which measurably raises response rates. Self-hosting also removes the third-party sub-processor from your privacy policy entirely: survey responses often contain PII, and keeping them on your own server matters for GDPR-sensitive and regulated industries. The Community Edition has no response caps or tier-gated features, so core functionality and your data stay accessible regardless of any subscription. Next.js on PostgreSQL, AGPLv3.

The de facto dashboard of observability: Grafana is the open-source frontend that turns the data stores you already run into interactive graphs. It does not store metrics itself; it connects to the data stores you already run and turns their contents into interactive dashboards. Supported sources number over 150 via plugins: Prometheus, Loki, Tempo, InfluxDB, Elasticsearch, MySQL, PostgreSQL, Microsoft SQL Server, AWS CloudWatch, Azure Monitor, Google Cloud Monitoring, and many more. Dashboards are built from a large library of panel types (time series, heatmaps, tables, gauges, logs) with template variables for reusable, parameterized views. Unified alerting evaluates rules against any connected data source, not just Prometheus, and routes notifications to Slack, PagerDuty, email, and other channels with grouping and silencing - unlike Prometheus Alertmanager, a single rule can combine a Loki log pattern, a PostgreSQL query result, and a CloudWatch metric. Dashboards serialize to JSON and data sources configure via provisioning files, so the entire observability setup can live in Git and deploy repeatably across environments. Explore mode adds ad-hoc querying outside dashboards, with split view for correlating a metric spike against the matching log lines, and access control spans organizations, teams, folder permissions, and OAuth, LDAP, and SAML integration. Written in Go and TypeScript, AGPL-licensed. Self-hosting gives you unlimited users, dashboards, and queries at flat hosting cost, without Grafana Cloud's usage-based pricing.

The most widely deployed open-source BI tool, Metabase is a visualization and query layer that sits on top of your existing databases without ingesting or copying data. Non-technical users ask questions through a visual query builder with drill-through menus that answer follow-ups like "broken down by month" without writing a new query, while analysts use the native SQL editor with variables and templates for complex work. Questions assemble into interactive dashboards with filters, auto-refresh, fullscreen mode, and custom click behavior, and dashboard subscriptions email or Slack scheduled reports to stakeholders. It connects to 20+ data sources including PostgreSQL, MySQL, MongoDB, SQL Server, BigQuery, Snowflake, Redshift, and ClickHouse - always querying in place, so there is no second data store to secure, sync, or pay for, and results are always current. Models and metrics let a data team define official, reusable starting points so self-service stays consistent, collections with permissions organize content, and alerts fire when a metric crosses a threshold. The practical effect is cutting the ad-hoc query queue that lands on the data team, since non-technical staff can answer their own questions. Written in Clojure, licensed AGPL, and shipped as a single JAR or Docker image with an embedded application database - a working BI instance runs before most tools finish their installer - the open-source edition has no limits on users, dashboards, or connected databases, where commercial BI platforms price per viewer as well as per creator.

Website analytics, uptime monitoring, and server status - three tools most teams run separately - combined in Tianji, an open-source observability platform. The analytics layer tracks page views, unique visitors, referrers, and UTM parameters with a lightweight cookie-less script, which keeps collection GDPR and CCPA friendly. The uptime monitor checks availability and latency on configurable intervals, accepts passively reported results, and publishes public status pages for incident communication. Server status agents report CPU, memory, disk, and network metrics with threshold-based alerts, and notifications route through webhooks, Slack, Telegram, and other channels with noise control. It also includes anonymous telemetry for tracking deployments of your own open-source projects, surveys, waitlists, team collaboration, and an OpenAPI interface for integrations and exports. The consolidation is the point: traffic analytics, uptime checks, and server metrics share one interface and one alerting layer, so diagnosing an incident does not mean hopping between Google Analytics, Uptime Kuma, and Prometheus - and the built-in public status pages replace a separate paid Statuspage-style subscription. Because collection uses no cookies with IP truncation and aggregation by default, basic traffic measurement requires no consent banner. Built in TypeScript under the Apache 2.0 license and inspired by Umami and Uptime Kuma, it is deliberately right-sized for independent developers and small SaaS teams whose monitoring needs are real but lightweight.

Marketing campaigns and transactional mail from one open-source platform: Notifuse is a modern, self-hosted alternative to Mailchimp, Brevo, and Klaviyo without per-email or per-contact pricing. Built with Go and React on PostgreSQL, it separates concerns cleanly: a drag-and-drop visual builder composes responsive templates from MJML components with Liquid variables like {{ contact.first_name }} and per-template version history; campaigns add A/B testing across subject lines, content, and send times; and a REST transactional API serves application-triggered mail. Delivery routes through your choice of provider - Amazon SES, Mailgun, Postmark, SendGrid, SparkPost, Mailjet, or plain SMTP - with multi-provider failover. Contacts carry custom fields and a full activity timeline (messages, profile changes, webhook events), and real-time segmentation builds dynamic rules over properties, activity, and subscriptions. Event-driven automations create behavioral sequences, a notification center gives recipients self-service preference management, and an S3-compatible file manager handles images with CDN delivery. Multi-tenant workspaces with isolated databases and custom domains suit agencies. Open and click tracking report engagement in real time.

Unlimited domains, unlimited keywords, daily Google position checks with stored history and trend charts: SerpBear is an open-source search engine rank tracker. Retrieval works through your choice of third-party SERP APIs - ScrapingAnt, ScrapingRobot, SerpApi, SearchApi, HasData - or your own proxy IP pool, and a flexible scrape-strategy system (Basic, Custom, or Smart, set globally or per domain) works around Google's removal of the 100-results-per-page parameter by choosing how many pages to check per keyword. Google Search Console integration adds real visit counts, impressions, and click-through rates per tracked keyword and surfaces top-performing pages and countries; Google Ads integration supplies monthly search volumes and auto-generates keyword ideas from your site's content. Email notifications report position changes daily, weekly, or monthly, a built-in REST API feeds dashboards and reporting tools, and data exports to CSV. Built with Next.js on SQLite, deployed via Docker, installable as a PWA on mobile - with no per-keyword or monthly SaaS fees.

Stocks, ETFs, crypto, bonds, precious metals, and cash across every account and currency, in one privacy-first dashboard: Ghostfolio is open-source wealth management software. The deliberate design decision is no brokerage linking: positions enter by manual entry, CSV import, or the REST API, so your holdings never pass through a data aggregator. Performance is measured as return on average investment across Today, WTD, MTD, YTD, 1Y, 5Y, and Max timeframes, with benchmark comparison against indices like the S&P 500, dividend tracking, and allocation breakdowns by asset class, region, and sector. A static X-ray analysis flags concentration and other portfolio risks, and a FIRE calculator projects progress toward financial independence. Multi-currency support converts holdings using historical exchange rates, market data comes from Yahoo Finance and CoinGecko among other pluggable providers, and everything exports back out as CSV or JSON. Built with Angular and NestJS on PostgreSQL and Redis, shipped as Docker images for amd64 and ARM, with a mobile-first PWA interface, dark mode, and a distraction-free Zen mode. AGPL-licensed.

A campaign engine wrapped around a contact database: Mautic, the largest open-source marketing automation platform, replaces HubSpot or Marketo without per-contact pricing. Contacts arrive through forms, landing pages, imports, or the REST API and flow into segments: dynamic filters that update automatically from behavior, custom profile fields, or point scores. Segments decide who qualifies; campaigns decide what happens. The drag-and-drop Campaign Builder composes multi-step workflows from actions, positive/negative decision trees, and conditions (field values, tags, device type, segment membership, point thresholds), with static or relative delays, a Jump-to-Step action for moving contacts between branches, and handoffs that push contacts into CRMs or entirely different campaigns. Messaging covers email, SMS, and web/app push out of the box, with A/B testing and a drag-and-drop email builder; dynamic website content swaps page sections per known contact. Lead scoring assigns points for clicks and visits with decay for inactivity, while stages track funnel position. Native integrations cover Salesforce, HubSpot, Zoho, and Dynamics, plus a full REST API for custom sync. It runs on PHP and MySQL with cron jobs processing campaigns and segment rebuilds - self-hosting keeps your entire contact database and behavioral history under your control.

No cookies, no fingerprinting, no cross-site tracking, no personal data collection - Umami's privacy contract is the foundation of the open-source web analytics platform. IP addresses are hashed rather than stored, which makes it GDPR, CCPA, and PECR compliant by default - the consent banner can come off the site entirely. The tracking script is under 2 KB, roughly 20x smaller than Google Analytics, so measurement stops being a page-weight tax. The dashboard covers the core metrics - pageviews, visitors, bounce rate, visit duration, referrers, browsers, devices, and countries - with any date range and filtering by country or device. Beyond pageviews, custom events track clicks, form submissions, and signups via a data attribute or one JavaScript call, and advanced reports add funnels, user journeys, retention and cohort analysis, goals, and automatic UTM campaign tracking. Anonymous session views show individual visitor activity without identifying anyone. Teams share websites with role-based access, one instance manages unlimited sites, and a full REST API exposes every metric programmatically. MIT-licensed and self-hosted on PostgreSQL or MySQL via Docker, your analytics data never leaves your infrastructure.

Traffic analytics, real-user performance monitoring, and client-side error tracking - normally three tools - in one cookieless, privacy-first dashboard: Swetrix. The Community Edition ships the same core engine as the cloud product - a NestJS API with ClickHouse for high-volume event storage, MySQL for relational data, and Redis for caching, fronted by a React dashboard and a ~5 KB tracking script with official packages for 20+ frameworks including Next.js, WordPress, and Shopify. Traffic analytics cover pageviews, referrers, UTM campaigns, geolocation, sessions with page flows, funnels, and custom events - all anonymized server-side with no cookies, no cross-device tracking, and no consent banner required for GDPR compliance. Performance monitoring records real-user metrics per pageview: TTFB, DNS and TLS timing, and render times, so regressions surface in the same place as traffic. Error tracking captures unhandled JavaScript exceptions automatically with formatted stack traces, filename/line metadata, affected browsers and pages, first/last-seen timestamps, and a resolve workflow - replacing a separate error monitoring subscription for many teams. Alerts fire to email, Slack, Telegram, Discord, or webhooks on traffic spikes, new errors, and custom events. If Plausible covers your traffic questions but you also want to know why the site broke, Swetrix answers both.

Between your databases and everything that consumes data - BI tools, embedded analytics, AI agents - sits Cube (formerly Cube.js), an open-source semantic layer. Metrics, dimensions, joins, and access rules are defined once as code in YAML, JavaScript, or Python, forming a governed data model that every downstream consumer shares, so "revenue" means the same thing in every dashboard. Caching is two-level: an in-memory cache absorbs bursts of identical queries, and declared pre-aggregations - rollup tables built in the warehouse or in Cube Store, Cube's distributed columnar engine, and refreshed in the background - deliver sub-second latency while cutting warehouse compute costs. The query planner routes each request to cache, rollup, or source automatically. Consumers connect through a Postgres-compatible SQL API (any tool that speaks Postgres works), plus REST, GraphQL, and a Meta API for model introspection. Row-level security and multi-tenancy are enforced in the layer itself, upstream of every client. Sources include Snowflake, BigQuery, Databricks, Postgres, MySQL, Presto, and Athena. Headless by design - bring your own UI.

Crypto portfolio tracking that inverts the SaaS model: rotki runs on your own machine, needs no email or account for the free tier, and keeps every wallet address, balance, transaction, and tax event in a local SQLCipher database encrypted with 256-bit AES. By default nothing passes through rotki-operated servers - a design choice that matters when cloud portfolio trackers concentrate exactly the identity-linked holdings data attackers want. Centralized exchanges (Kraken, Binance, Coinbase, Bitstamp, and more) connect through read-only API keys that can see but never withdraw; blockchain accounts cover Ethereum and its L2s, Bitcoin, Solana, Polkadot, and Kusama, with ENS resolution and your choice of RPC endpoint or your own node. rotki decodes on-chain transactions into readable events across major DeFi protocols - Aave, Uniswap, Compound, Curve, Lido - and generates profit-and- loss reports for tax season with customizable accounting settings, including FIFO, LIFO, and HIFO cost-basis methods, plus CSV imports for defunct exchanges. Optional premium sync is zero-knowledge, encrypting the database on-device before upload. AGPLv3-licensed and multiplatform, with a Docker package for server deployment.

Several EU data protection authorities have ruled Google Analytics deployments unlawful; Matomo (formerly Piwik) is the most complete open-source replacement - a full analytics platform with 30+ report types across visitors, actions, referrers, goals, and ecommerce. The self-hosted PHP/MySQL edition is free and keeps every byte of visitor data on your infrastructure, which matters more each year: several EU data protection authorities have ruled Google Analytics deployments unlawful, while Matomo configured for cookieless tracking is approved by France's CNIL for use without a consent banner. All reporting runs on 100% unsampled data - no extrapolation at high traffic volumes. The GDPR Manager handles data subject requests and deletion, with IP anonymization, retention controls, and Do Not Track support built in. A dedicated importer pulls your historical Google Analytics data so years of trends survive the migration. Core analytics cover campaigns, custom variables and dimensions, entry/exit pages, downloads, site search, and full ecommerce tracking with a comprehensive HTTP API for reporting and ingestion. Premium plugins extend the platform into Hotjar-class behavioral tooling - click and scroll heatmaps, session recordings, conversion funnels, form analytics, A/B testing - plus a tag manager and SAML SSO. For teams that need GA-equivalent depth with actual data ownership, Matomo is the realistic drop-in replacement.

Plex's own dashboard shows current streams and forgets everything else - which is why every Plex server admin eventually installs Tautulli, the analytics layer. This Python web application (descended from PlexWatch and Headphones) logs complete watch history - what was watched, who watched it, when, where, from which device and IP, and whether it played directly or transcoded - and turns it into clean Highcharts graphs of daily plays, concurrent streams, bandwidth, and platform breakdowns. The home page surfaces top statistics over configurable windows: most-watched content, most active users, stream type ratios. For running a server shared with family and friends, this is operational truth: spot the user forcing 4K transcodes on a phone, see which libraries earn their disk space, and track sync activity across users. The notification engine triggers on server events - playback starts, transcode decision changes, recently added media, server down - through dozens of agents (Discord, Telegram, Slack, email, webhooks) with fully customizable text and conditions, plus arbitrary script execution. Scheduled newsletters email your users a styled digest of recently added content. A comprehensive API exposes every statistic for dashboards like Homarr, and an official mobile app monitors activity on the go. Themed to match Plex/Web. GPL-licensed.

Built as a direct rejection of the adtech model, Plausible is the best-known privacy-first web analytics tool - lightweight, cookie-free, and open-source. It sets no cookies and stores no personal data: unique visitors are counted via a hash of IP plus User-Agent that rotates every 24 hours and is never stored raw, so no consent banner is required and GDPR compliance is structural rather than contractual. The tracking script is under 1 KB - orders of magnitude lighter than GA - and the dashboard is a deliberate contrast to GA4's sprawl: one fast-loading page with visitors, sources, top pages, countries, devices, and UTM breakdowns, filterable by any dimension. Custom events and goals track signups and clicks, Google Search Console integration pulls in search queries, scheduled email reports keep stakeholders updated, and the Stats API (v2) plus CSV export feed data anywhere. This is the AGPL-licensed Community Edition, the same Elixir codebase that powers Plausible's cloud service, running as three containers: the web app, PostgreSQL for accounts, and ClickHouse for event storage - which means self-hosters get direct SQL access to raw analytics data the cloud version never exposes. Traffic data stays entirely on your server, with no visitor caps or per-pageview pricing.

A spreadsheet whose formula language is real Python - full syntax plus the standard library, alongside familiar all-caps Excel functions: Grist is an open-source relational spreadsheet. Data lives in tables with typed columns and reference links, queried in formulas through lookupRecords and lookupOne, so one document can model what would otherwise take several joined spreadsheets. Trigger formulas compute values on conditions you define (timestamps, authorship, data cleanup, smart defaults), and an AI Formula Assistant generates formulas via OpenAI, Llama, or any OpenAI-compatible endpoint. Each document is a self-contained SQLite file, readable by any SQLite tool and trivially portable between hosts, with automatic snapshots and full-history exports. Layouts combine card, table, and chart widgets into dashboards, and granular role-based access rules restrict who sees which rows and columns - a design that made Grist a foundation of France's sovereign LaSuite workspace with 20,000+ government users. The Apache-2.0 grist-core edition ships SSO via OIDC and SAML, a REST API, webhooks, and forms; formula execution can be sandboxed with gVisor so untrusted documents cannot reach the network or each other.

Most design tools stop at prototyping; Quant-UX also measures how real users actually perform with the prototype. The visual editor creates prototypes that behave like real apps - functional input widgets, animations, form validation, data binding across screens, and business logic modeled with REST requests and decision elements. Design systems are first-class, with components, design tokens, and master screens; if you design elsewhere, drop in image files or import from Figma. Testing is a shared link or QR code - no installs on the tester's side. Define user tasks up front, and Quant-UX records every session: click heatmaps show where users found (or missed) actionable elements, user journey graphs expose lost users, drop-off charts reveal where tasks stall, and success rates and task KPIs are extracted automatically into a dashboard. An A/B test operator wires two design variants into one prototype and compares task duration, success rate, and interaction counts. In-prototype surveys collect qualitative feedback alongside the numbers, and an AI assistant generates prototype fragments like styled forms on request. The RepoCloud deployment runs the full stack - frontend, backend, and WebSocket server containers over MongoDB - so all test recordings and research data stay on your infrastructure.

A personal Strava on your own server: Endurain is a self-hosted fitness platform that keeps your complete workout history, GPS routes, and health data out of a vendor's cloud. It ingests the standard device formats (.gpx, .tcx, and preferred .fit with full sensor data) via manual or bulk upload, and syncs directly with Strava and Garmin Connect so migrating years of history is straightforward - Garmin sync covers activities, gear, and body composition. The dashboard shows activity feeds with weekly and monthly statistics, routes on maps, and distance, speed, and training-volume trends over time, with definable goals that update automatically. Gear tracking is notably deep: log wetsuits, bicycles, shoes, racquets, skis, and snowboards, assign default gear per activity type, and track individual components like bike chains against replacement mileage. Multi-user support with admin and user roles, follower features, per-activity privacy settings, and configurable sign-up (email verification, admin approval) make it usable for clubs and coaches as well as individuals. Auth is serious for a fitness app: MFA TOTP, OIDC/SAML SSO, and email-based password resets via Apprise. The stack is Vue.js over a Python FastAPI backend with PostgreSQL, plus weight, steps, and sleep logging, imperial/metric units, multi-language support, and third-party app integration.