Learn and code together on your own Wi-Fi.
French Algorithm, C and Python in the browser, with courses, a translator, chats, live coding and streams.
One computer hosts. Friends join from any phone, tablet or laptop on the same network.
Quick start · Features · Screenshots · Host panel · Editions · Security
AlgoWorld turns one computer into a small coding space for you and your friends. You start it with a double click, it shows a link and a QR code, and everyone on the same Wi-Fi opens it in their browser. Nothing is sent to the internet: accounts, code, chats and files stay on the host computer.
- Write and run code in French Algorithm (pseudo-code), C and Python, right in the browser.
- Learn with 3 courses (47 chapters, hundreds of runnable examples and quizzes) and a dictionary of every keyword.
- Work together: chats and groups, live coding on the same script, shared whiteboards, and streams where everyone sees your screen.
- Stay in control without being a king: the host manages accounts, storage and settings, but cannot read anyone's code, messages or screen.
Open PowerShell (press Start, type PowerShell, press Enter), paste this line and press Enter:
irm https://raw.githubusercontent.com/MrLemonOff/AlgoWorld/main/install.ps1 | iexFor the Full edition (with offline translation):
& ([scriptblock]::Create((irm https://raw.githubusercontent.com/MrLemonOff/AlgoWorld/main/install.ps1))) -FullIt downloads the latest release, installs it in %LOCALAPPDATA%\Programs\AlgoWorld, adds AlgoWorld to your Desktop and Start menu, and opens it. A setup window shows the progress while AlgoWorld prepares itself the first time.
-
Open the latest release and download one file:
Download What you get AlgoWorld-Lite.exe Everything except offline text translation. About 800 MB once installed. AlgoWorld-Full.exe Everything, with offline text translation (English, French, Arabic). About 1.8 GB once installed. AlgoWorld-Lite.zip / AlgoWorld-Full.zip The same, as a folder you extract yourself. Then double-click AlgoWorld.exe or start.bat inside it. -
Double-click it. A setup window shows the progress while AlgoWorld installs itself the first time (a few minutes, internet needed once). Then AlgoWorld opens in its own window, like a desktop app.
Windows may show "Windows protected your PC" because the exe is new and not yet known to Microsoft. Click More info, then Run anyway. The PowerShell line above avoids this screen.
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The Host panel shows the link and a QR code for your friends. Create your own account first, then open the Host panel from the menu.
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Friends connect to the same Wi-Fi and open the link (or scan the QR code), then create their account.
Closing the AlgoWorld window stops it. Open the exe again to start it: the next starts take a few seconds.
If Node.js is not installed, AlgoWorld offers to install it for you (with
winget), or opens the Node.js download page. If Windows asks about the firewall the first time, allow Private networks, otherwise friends cannot connect. The exe installs AlgoWorld in%LOCALAPPDATA%\Programs\AlgoWorld. Your data stays there in thedatafolder.
git clone https://github.com/MrLemonOff/AlgoWorld.git
cd AlgoWorld
./start.shstart.sh installs, builds and starts AlgoWorld (Lite). Use ./start.sh full for the Full edition.
| Feature | What you can do | |
|---|---|---|
 |
Code | Write and run French Algorithm, C and Python. A real console with keyboard input, syntax colours, suggestions, run history. Python runs in a locked-down sandbox in the browser. |
 |
Translator | Turn an algorithm into C or Python (and back) while you type, with notes on what needs checking. |
 |
Courses | Algorithm, C and Python from zero: 47 chapters, examples you run inside the page, quizzes, saved progress. |
 |
Dictionary | Every keyword, type and function of the three languages side by side, searchable. |
 |
Planning | Whiteboards with flowchart shapes and templates. Draw a flowchart from your algorithm, or write an algorithm from your flowchart. |
 |
Chats | Direct messages and groups, code that stays coloured and runnable, replies, forwards, pictures and files, read receipts, blocking. |
 |
Invitations | Invite a friend to write in your script or draw on your board live, with a temporary (5 minutes) or permanent invitation. |
 |
Stream | Show a PDF, PowerPoint, Word file, video, picture, web page or your code to a group with a 6-character code. Everyone sees your page, zoom, pointer and pen. |
 |
Selection translator | Select any text to read it in English, French or Arabic, fully offline (Full edition). |
 |
Any device | Phones, tablets and computers. Light and dark themes, bigger text, fewer animations. |
 |
Host panel | Dashboard, users, data, logs and settings for the person running AlgoWorld. |
 Home |
 Code (light theme) |
 Python, offline in the browser |
 Translator: Algorithm to C |
 Courses |
 A chapter |
 Chats with runnable code |
 Planning: flowcharts |
 Dictionary |
 Stream |
 Host panel: dashboard and join link |
 Host panel: users |
 Sign in |
 On a phone |
The person who starts AlgoWorld is the host. The host panel is in the menu of the AlgoWorld window, and only works on the host computer with the secret link printed in the AlgoWorld window (a new link every start). Nobody else can open it, even on the same Wi-Fi.
| Tab | What the host can do |
|---|---|
 Dashboard |
See accounts, who is online, activity per day, busy hours, languages used, devices and storage. Numbers only. |
 Users |
Create accounts, rename, set a new password, sign someone out, mute in the chat, ban for a while or for good, delete an account. Several at once. |
 Data |
See what takes space, download a backup, restore one, clean old logs, runs, chat messages and caches. |
 Logs |
Sign-ins, new accounts, host actions and security events. Search, export to CSV, clear. |
 Settings |
Name, new accounts on or off, chat on or off, an announcement banner, time limits, and closing any page or course. |
What the host cannot do. The panel never shows anyone's code, messages, pages, screen or typing, and the host has no special access to other people's scripts, boards, chats or streams. There is no "admin account" and no master password.
Pick the edition by downloading AlgoWorld-Full or AlgoWorld-Lite. To switch later, run start.bat full or start.bat lite (or ./start.sh full / ./start.sh lite).
| Full | Lite | |
|---|---|---|
| Code, Translator, Courses, Dictionary, Planning, Chats, Invitations, Stream, Host panel | Yes | Yes |
| Offline selection translator (English, French, Arabic) | Yes | No |
| Disk space (approximate) | 1.8 GB | 800 MB |
| First download | about 700 MB | about 250 MB |
The Full edition adds the addons/translation engine (transformers.js with ONNX Runtime) and four small OPUS-MT models in models/translation. You can add them at any time with npm run translation.
- Host computer: Windows 10 or 11, macOS or Linux, with Node.js 20.9 or newer (the LTS version is best) and about 1 to 2 GB of free space.
- Friends: any recent browser (Chrome, Edge, Firefox, Safari) on the same Wi-Fi or on the host computer's hotspot.
- Internet: only for the first install. After that AlgoWorld works fully offline.
- Optional: Microsoft Office or LibreOffice on the host computer renders PowerPoint and Word files exactly in streams. Without them the browser draws those files itself.
- The host computer and the friends must be on the same network (the same Wi-Fi, or the host computer's own hotspot).
- Friends open the address shown in the host panel, for example
http://192.168.1.20:3000, or scan its QR code. - They create an account on the sign-in page (the host can turn this off and create accounts in the Users tab instead).
If a friend cannot connect: check they are on the same Wi-Fi, allow AlgoWorld (Node.js) in the Windows firewall for Private networks, and avoid guest networks that isolate devices.
git clone https://github.com/MrLemonOff/AlgoWorld.git
cd AlgoWorld
npm ci # install
npm run build # build the pages once
npm start # start and open the host panel
npm run dev # development mode with hot reload
npm run translation # add the offline translation engine and models
npm test # language, course and realtime/security testsEverything works without configuration. These environment variables are optional:
| Variable | Default | Meaning |
|---|---|---|
PORT |
3000 |
Port to use (the next free port is taken if it is busy) |
HOST |
0.0.0.0 |
Network interface to listen on. 127.0.0.1 keeps AlgoWorld on this computer only |
DATA_DIR |
./data |
Where accounts, scripts, chats and files are stored |
TRANSLATION_MODELS |
./models/translation |
Folder of the offline translation models |
STREAM_UPLOAD_MAX_GB |
20 |
Total space that stream uploads may use (one file: 1 GB, or 4 GB from the host computer) |
WEBCACHE_MAX_MB |
512 |
Cache for web pages shown in streams |
AW_NO_OFFICE |
unset | 1 never uses Office or LibreOffice to convert files |
AlgoWorld/
start.bat, start.sh one-click launchers
launcher/ source of AlgoWorld.exe and the Full/Lite installers (C#, launcher/build.bat)
server/ Express + Socket.IO server, JSON storage, security, host panel API
src/app/ Next.js pages (code, courses, chat, planning, stream, host panel...)
src/components/ shared React components
src/lang/ parsers, interpreters and translator for Algorithm and C
src/data/ courses and dictionary
public/workers/ sandboxed Python worker (Pyodide)
addons/translation/ optional offline translation engine (Full edition)
scripts/ asset copy, course index, translation download, tests
docs/ logo, icons and screenshots for this README
Next.js 16 and React 19 for the pages, Express 5 and Socket.IO for the server, Yjs for live collaboration, CodeMirror 6 for the editor, Pyodide for Python, pdf.js, Excalidraw and rrweb for streams and whiteboards, transformers.js for offline translation. Data is stored in plain JSON files with atomic writes and backups. See THIRD-PARTY-NOTICES.md for every project AlgoWorld builds on.
- Everything is stored in the
datafolder on the host computer. Delete it to start from zero. - Take backups from Host panel > Data > Download a backup, and restore them from the same place.
- Passwords are stored as bcrypt hashes, never in clear.
- To update AlgoWorld, replace the program files and keep the
datafolder.
AlgoWorld is built for trusted local networks (home, club, class). It has rate limits, CSRF protection, strict content security policy, a sandbox for Python and for streamed pages, upload checks and many other protections, and the host panel only opens on the host computer. Do not expose it directly to the internet. See SECURITY.md for the details and how to report a problem privately.
Issues and pull requests are welcome. Please read CONTRIBUTING.md and CODE_OF_CONDUCT.md first.
AlgoWorld is released under the MIT License. Copyright (c) 2026 LMN.
The third-party libraries, fonts, icons and models it uses keep their own licenses, listed in THIRD-PARTY-NOTICES.md.