NETROOM
Excalidraw is a virtual whiteboard for diagrams in a hand-drawn style: architecture sketches, user flows, wireframes and anything else that is quicker to draw than to describe. It runs in the browser with no sign-up - open a tab and start drawing. There are libraries of ready-made shapes, export to PNG and SVG, collaboration over a link with end-to-end encrypted rooms, and files you can keep locally or in your own storage. Open source, with a self-hosted option for teams.
Squoosh compresses images in the browser: drop a file in, pick a format and a quality, download the result. A slider puts the original and the compressed version side by side, so you can see exactly where artefacts start and stop just before them. It handles a range of formats, each with its own controls - from a single quality dial to the codec's own parameters. Nothing is uploaded: the work happens on your device, and it runs offline once installed as an app. Built by Google Chrome Labs, open source, no sign-up.
The Cyber Swiss Army Knife, built by the UK's GCHQ. You chain operations into a "recipe" and push text or a file through it: base64, XOR, AES, DES, Blowfish, hashes, hexdumps, X.509 and IPv6 parsing, archive extraction, charset conversion. Everything runs in the browser - nothing is sent to a server, and you can download the page and use it offline. Apache 2.0 plus Crown Copyright. Invaluable for picking apart logs, dumps and suspicious payloads.
A Swiss army knife for PDFs in the browser, running on your own server: merge and split, rotate, compress, convert to and from office formats, OCR, sign, redact, and chain operations through a REST API - over fifty tools in all. The point is that files never reach someone else's cloud. One docker run gets you going, and a desktop client and Kubernetes charts exist too. It is open core: the base is open source while some capabilities sit behind paid Server and Enterprise plans.
An answering engine that runs on your own hardware: it searches through SearxNG and writes the answer with the model you pick - Ollama locally, or OpenAI, Claude, Gemini and Groq by API key. Answers come with cited sources, and there are Speed, Balanced and Quality modes plus web, discussion and academic search, images, video, file uploads and history. This is the project formerly known as Perplexica - it was renamed in 2026, so plenty of Docker images and guides still use the old name. MIT.
A Python library for building feed readers - it fetches and stores Atom, RSS and JSON feeds, tracks read and important flags, handles tags, full-text search, OPML import/export and feed discovery. Deliberately framework-agnostic: it hands you the engine and stays out of the way. An optional Flask web app and a CLI ship with it, so you can also just run it as-is. Pure-Python dependencies, a stable fully typed API, plugin hooks, BSD-3 licence, and steady active development.
A Django-based document management system: drop files in and Mayan renders previews, runs OCR, sorts them into document types, builds tree indexes and pushes them through workflows with states and transitions. You get file versioning, metadata, tags, full-text search, per-document permissions, a REST API and antivirus scanning. It installs via Docker on PostgreSQL, Redis and a background worker queue, and it is fairly resource hungry. Code lives on GitLab; mayan-edms.com returned 403 on our check, though the repo is alive.
Project management gathered into one system: scheduling with Gantt charts, a portfolio of many projects, tickets and requests, workload tracking, risks, budgets and finance, deliverables, and agile methods alongside classic ones. Add collaboration - notes, attachments, links between records - and fine-grained rights management. It is PHP, self-hosted and free to install; hosting, support, training and custom development are the paid options. A long-running French project; the site has moved from .org to .com.
A home assistant that keeps your data local: device dashboards, automation scenes, energy tracking and voice control. It talks to Zigbee, Matter, MQTT and native integrations, covering thousands of devices, and scenes are built by clicking rather than by writing YAML. Installation is a single Docker command on any Linux box - Raspberry Pi, mini PC, Synology NAS or an old laptop. The core is free and open source with no feature caps; the optional Gladys Plus subscription adds end-to-end encrypted remote access, mobile apps and AI features.
A tool for group decisions rather than another chat room: discussion with context and documents in one place, then a vote where everyone states the reasoning behind their position. Each thread closes with a recorded outcome, owners and next steps, all searchable later. It works asynchronously, so decisions do not require getting everyone into a meeting. Built by a worker-owned co-op in New Zealand since 2011; the Rails code is AGPL and self-hostable. Hosted plans start at $399 a year.
Web analytics with no cookies, no personal data and no consent banner: the script is under a kilobyte and the report fits on one page, with no half-day segment builder. It counts visits, sources, pages, goals and campaigns - exactly what people actually look at. The code is open (AGPL) and the Community Edition runs on your own docker compose with ClickHouse and PostgreSQL. The cloud is paid, from $9 a month for 10k pageviews, with a 30-day trial and no card. There is a GA4 importer.
Distributed storage built for absurd numbers of small files: a master tracks volume metadata while blobs sit on volume servers at 16 bytes of metadata each, giving O(1) disk access. On top, the filer adds an S3-compatible API, WebDAV, FUSE mounts and an HDFS interface. There is rack- and datacentre-aware replication, erasure coding for warm data, TTL expiry and AES256-GCM encryption. Apache 2.0, 34k stars on GitHub, and a relentless commit pace.
Corporate video conferencing and messaging on your own server: group conferences, chats, recording and SIP/H.323 gateways. The free edition is real but tightly capped: up to 1,000 users online, of which 10 may host group meetings, 10 participants per conference, one browser guest link per meeting and one SIP/H.323 connection. It installs on Windows Server, Debian, CentOS Stream or Docker. The software is proprietary, and the free licence has to be renewed on the website every year.
A container registry that stores everything natively in OCI format - no proprietary internal layout you later have to dig your data out of. It implements the OCI Distribution Spec, so plain docker, podman, helm and Kubernetes all work against it unchanged. Beyond images it holds any OCI artifact: charts, SBOMs, signatures. Production-ready and deliberately vendor-neutral. Written in Go, Apache-2.0 licensed, documented at zotregistry.dev, and the repository sees steady activity.
A reverse proxy for the homelab, configured entirely from the browser and without restarts. HTTP/2 and WebSocket proxying, Let's Encrypt certificates over ACME with auto-renewal, TCP and UDP stream forwarding, uptime monitoring, a web SSH terminal in the panel, IP and country allow/block lists, and live visitor statistics. There is a plugin system - the ZeroTier network controller now lives in a separate ztnc plugin. One Go binary for Linux (ARM and RISC-V included), Windows and SBCs. AGPL-3.0.
CCTV software for Linux: it captures, analyses, records and monitors camera feeds - IP, USB and analogue via capture cards. Zone-based motion detection, schedules, alerts, per-user access control, H.264 and H.265, and it scales out across several machines when one stops coping. The web UI looks dated but it is battle-tested: roughly 30k commits and active Slack and Discord channels. GPL-2.0. The maintainers advise against building from source - use the packages for Ubuntu, Debian, RHEL, Fedora or Arch.
An IRC bouncer: it stays connected to networks while you are away and replays the buffered messages when your client comes back. Nothing said in a channel goes missing, and one account looks the same from several devices. The buffer is configurable per channel, and you get SSL/TLS, a web admin panel, per-user and per-network settings, and modules in C++, Perl and Python. Passwords are hashed with Argon2. Apache-2.0. Building needs CMake 3.13+ and GCC 8+ or clang 5+. Quiet but maintained.
Your own upload server for files and screenshots, built around ShareX: set it up once and Print Screen turns straight into a short link. Version 4 is a full rewrite - React with Mantine, folders and tags, a URL shortener, image compression, video thumbnails, webhooks, quotas, invites, PWA support and custom themes. Login via OAuth2, 2FA and passkeys. Files go to local disk or S3, metadata to PostgreSQL. MIT licensed. Needs Docker and a CPU with AVX support.
An organisation-grade mail and calendar server: email, calendars, contacts, tasks, files and chat in one web client, reachable from ordinary mobile and desktop clients. It has been around for over twenty years and claims more than 200 million mailboxes deployed. The core server is open source, but the parts that matter at scale - HA clustering, encryption, Outlook integration, mobile push sync, archiving - sit in the paid Standard and Professional editions. A common Exchange replacement, but not a free one.
A desktop wiki for personal notes: pages link to each other, sit in a folder tree, and are stored as plain text files with wiki markup - editable in any editor and happy in git. Formatting, images, attachments and autosave come as standard, and plugins add tasks, equations, a tray icon and version control. Nothing is in the cloud and nothing is a subscription. Needs Python 3.10+ and GTK+ 3.18; runs on Linux, Windows via MSYS2 and macOS. GPL-2.0, and still maintained after many years.
Code time tracking: VS Code and JetBrains plugins record how long you spend per project, language, file and branch, and the dashboard turns that into charts with time-range filters. Existing data imports from WakaTime or a WakAPI instance, so you keep your history. There are README badges, public stats pages and leaderboards, with GitHub or email login. AGPL-3.0 licensed. Use the public ziit.app or self-host with Docker - the self-hosted route wants TimescaleDB.
A headless CMS that lives inside your Next.js app: the config is TypeScript, collections are described in code, and the admin panel mounts into the same project - no separate backend to run. It ships the Lexical rich text editor, blocks, relationships, uploads, access control, hooks, drafts and versions, and localization. Data goes to Postgres via Drizzle or to MongoDB. A Local API skips HTTP entirely, with REST and GraphQL alongside. MIT licensed.
A full real-time strategy game on the Spring engine - free, open source, with no in-game currency and nothing to buy for an edge. Physics and terrain are the point: projectiles actually fly, and you can crater the battlefield, dig canals and reshape hills into your own defences. Over a hundred units with distinct mechanics, a campaign, AI skirmishes, multiplayer from 1v1 to 16v16, and Planet Wars - a long-running online campaign with a strategic metagame. Ladder, tournaments and populated servers.
A self-hosted error tracker you buy once - $299, no subscription, no event quotas, no per-seat billing. Point your existing Sentry SDKs at your own instance and nothing in the app has to change. It groups errors and shows backtraces, breadcrumbs, request details and local variables, alerting through Slack, Discord, Teams, email, webhooks or PWA push. Source maps, release tracking and MCP access for AI tools are included. Docker install, 1 GB RAM is enough. Source is shipped, but the licence is proprietary.
An ALM suite that keeps product, project, QA and documents in one place: stories, tasks and bugs stay linked, and product owner, developer and tester roles are kept distinct. It supports Scrum, waterfall and kanban, ships reports and metrics, DevOps integrations, test automation and an org-management module. PHP 5.6 or newer is the requirement. The open edition is dual-licensed AGPL and the vendor's own ZPL; Biz, Max and Cloud editions are paid, and some features live only there.
A gallery-first CMS for people who show work rather than write posts: images, audio and video go into albums, with a blog and free-form pages alongside. User rights, multilingual content and some fifty ready themes mean an illustrator's, photographer's or musician's site comes together without coding. Plain PHP and MySQL, so cheap shared hosting is enough. GPL-2.0 or later, with paid support available. An old project but a live one - 1.6.8 shipped in May 2025 and the forum and tracker are active.
An open S3-compatible object storage server - the project formerly known as S3 Server. Two jobs it does well: standing up a local S3 for CI tests so you never pay for a real bucket, and putting one S3 API in front of several very different backends at once - local files, memory, Azure and Google Cloud. Location constraints decide where an object physically lands. Part of Scality's Zenko platform, Apache-2.0 licensed. Runs on Node.js, deploys with Docker, and the repo is still busy.
Listening together in a room: people take turns queuing something up - songs, talks, gameplay clips - and everyone watches it at the same time, with chat and voting alongside. Media comes from external sources, YouTube and SoundCloud out of the box, so you host no library of your own. The core, u-wave-core, is a Node server with an HTTP API, paired with a separate web client. It needs SQLite, a 64-character hex secret and a YouTube API key if you want YouTube. MIT licensed.
Editors' picks