Best new learning, design and developer resources: 17 October

17 October was a big one. Thirty free tools and websites went into the directory, plus ten open-source projects from GitHub. To make it easier to scan, I've sorted them into notes and everyday utilities, learning and research, design resources, finding more tools, PDFs and data, and developer and AI agent projects. Quick heads-up: features and pricing change, so check each tool's own page before you commit.

Notes, little automations and everyday helpers

Trilium Notes is a free, open-source note-taking app that keeps your notes in a deep tree, with labels, relations, templates and full-text search. It runs offline on your desktop and handles rich text, code, canvas, mind maps and encrypted notes. The catch? There's no official mobile app, and syncing needs a server you host yourself. Etherpad is a free, open-source editor where several people type in the same document at once, each in their own colour. There's chat, plus a time slider to replay every change. You can self-host it or use a public instance, though how reliable those are varies.

AutoHotkey is a free, open-source scripting language for Windows. Use it for keyboard shortcuts, text expansions and small automations. Everything, from voidtools, indexes file and folder names on Windows and shows results the moment you start typing. By default it searches names, not what's inside the files. CopyQ is a free, open-source clipboard manager with a searchable history, tabs, tags and custom commands. On the Mac, AltTab gives you Windows-style window switching with a preview of every open window. The core switcher is free; search and extra styles need an optional Pro licence.

World Time Buddy puts several cities side by side so you can find a meeting time that works for everyone. The free version covers a handful of locations and shows ads. A Soft Murmur is a free website for mixing ambient sounds like rain, waves and coffee-shop chatter, with a timer that stops or fades the sound. And calibre is a free, open-source e-book manager. It organises your library, converts between formats such as EPUB, AZW3 and PDF, and syncs books to e-readers. It can't open books protected by DRM, though.

Learn something, type faster, research smarter

Khan Academy is a non-profit with free lessons, practice exercises and videos, all the way from early school level to university. Practice is mastery-based, but there are no accredited certificates. freeCodeCamp is another non-profit, with free, self-paced curricula in web development, JavaScript, Python and data analysis. It's built around interactive exercises, real projects and free certifications. MIT OpenCourseWare publishes lecture notes, videos, problem sets and exams from thousands of MIT courses, no sign-up needed. Just know there's no grading, and some recordings are older.

Exercism is a free, open-source platform for practising programming in more than 70 languages. You get automated feedback plus free reviews from volunteer mentors, though waiting times vary. Keybr is a free typing tutor that builds lessons around your weak keys and tracks detailed stats. For research, Connected Papers draws a visual graph of papers related to one you enter, which is handy for literature reviews. The free plan gives you a limited number of graphs each month.

Icons, colours, illustrations and images to use

Iconify pulls more than 200,000 icons from open-source sets into one searchable library and shows each set's licence, which differs from set to set. Remix Icon is a free, open-source set of more than 3,000 neutral-style icons in outlined and filled versions, free for personal and commercial projects. Hero Patterns gives you repeatable SVG background patterns with adjustable colours and opacity. favicon.io makes a favicon and app icons from text, an image or an emoji, and hands you the HTML code to add them.

Adobe Color builds palettes with a colour wheel and harmony rules, pulls themes out of images and checks contrast and colour-blind safety. Saving palettes needs a free Adobe account. Openverse is a free, open-source search engine for more than 800 million openly licensed and public domain images and audio tracks, run as part of the WordPress project. It doesn't verify licence details for you, so check each work before you reuse it. Storyset, from Freepik, offers customisable illustrations with simple animations; the free licence requires attribution. Lapa Ninja is a gallery of more than 7,000 landing page designs for when you need ideas. And PhotoGIMP is a free, open-source patch that makes GIMP 3 feel familiar to Photoshop users. You'll need GIMP installed first, and it doesn't add Photoshop-only features.

Where to find even more tools

There's An AI For That is a free directory of thousands of AI tools you can search by task, with pricing details, ratings and alternatives. The layout is busy, and it includes sponsored listings. SaaSHub is an independent marketplace for finding and comparing software alternatives, with reviews and pricing notes; featured listings show up near the top. DevHunt is a free, open-source launch platform where the community upvotes new developer tools each week. Many of them are early-stage.

PDFs, file conversions and data wrangling

iLovePDF covers everyday PDF jobs: merging, splitting, compressing, converting, signing and protecting files. The free web version has file size and usage limits, and it uploads files to its servers, so think twice before using it for anything sensitive. CloudConvert converts between more than 200 formats with adjustable quality settings and a daily number of free conversions. JSON Crack is a free, open-source tool that turns JSON, YAML, CSV and XML into an interactive graph in your browser, where you can also format, validate and query the data.

Open-source developer and AI agent projects on GitHub

Ten free, open-source projects came in too. Whiteboard is a desktop canvas where you and an AI coding agent such as Claude Code or Codex design software together, with diagrams, semantic diffs and decision logs. You can't edit files inside the app yet, and anonymous telemetry stays on until you turn it off. reladraw is a text-based diagram language that sits somewhere between Mermaid and draw.io. diffle is a keyboard-first diff viewer for reviewing Git diffs and GitHub pull requests in the browser, then passing your comments to an agent or posting them as a pending review.

MockServer mocks HTTP, gRPC, WebSockets and AI chat APIs from one port for testing. k10s is a Kubernetes terminal UI that works with the mouse and comes with an AI assistant. Harness Terminal is a GPU-rendered macOS terminal that pings you when a coding agent stops or asks for approval; it needs an Apple silicon Mac on macOS 15 or later. explainroo lets a coding agent make narrated explainer videos, and it needs Node.js and ffmpeg. Big Arrow on the Screen lets agents draw arrows and notes over any macOS window to show you where to click. Screen Memories searches the photos and videos on your Mac from a plain-language description, running every model locally. Langchain.rb is a Ruby gem that gives Ruby and Rails developers one interface for lots of language model providers, whose costs are separate. These are all third-party projects provided as-is by their maintainers, so review each project's licence, code and security before you install anything.

Want to see them all side by side? Every one of these sits in the full directory with the rest of the collection, and the filters for pricing, platform and category help you narrow things down fast.