No cookies, tracking, or ads

• This thing has no cookies, tracking, or advertising. No signup required. GDPR compliant.
• You can wipe all stored data at any time by telling your browser to clear its stored data for this website.
• There's no guarantee or warranty that this site is fit for any purpose; it is freely available as-is.
• Please don't do anything silly with this site. If you do it anyway, don't blame me if it goes wrong.
• No AI-generated code: 100% of code/assets are written/created by a human with far too much spare time.

Want to know more about what this is, how it works, and why it exists?

This is LethargicOS.

I decided to try and build an “operating system” written in JavaScript that runs inside a web browser. It has its own filesystem, apps, and command-line interface. It installs itself in your browser storage so that data is saved between visits, and this also lets it work without an internet connection: just visit the URL, even if you're offline.

After you hit the start button below, the site will “boot up” and launch the installer. This will start to store files in your web browser's site-specific storage (note: nothing has been stored yet). To begin with, all of the operating system files are installed, and any files you create later will be stored too. However, you retain full control: none of ths data will be sent outside your browser, and you can access and edit all of it. Yes, you can even start editing the operating system files from inside the OS itself, if you like! Although… maybe don't try this unless you know what you're doing, as you can break the OS and leave your version of the site in an unusable state until you wipe and reinstall.

As for why it exists? Uh, because I could, I guess. Modern browsers are pretty powerful, and I think it's pretty fun to explore their potential and see what I can make them do.

Software License

This software is available under the terms of the MIT License, as follows:

Copyright © 2025 TerrorBite (Lethargic Lion)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

• The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
• THIS WEBSITE AND SOFTWARE ARE PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
• IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE WEBSITE OR THE USE OR OTHER DEALINGS IN THE WEBSITE, TO THE EXTENT PERMITTED BY APPLICABLE LAW.

Data and Privacy

Definition of Personal Information

“Personal Information” means any information relating to an identified or identifiable natural person. Generally, this means information which identifies a person (name, address, other personal information). For a legal definition of “Personal Information”, consult the definition given in Section 6(1) of the Privacy Act 1988 (Commonwealth of Australia) and the definition in Article 4 of the General Data Protection Regulation (EU) 2016/679 (also known as GDPR).

Data storage

LethargicOS is written as a Web Application, which runs within your browser and not on my server. “User Data” is data (in the form of files, text, images, preferences, etc) which belongs to you and which you generate within or supply to the Web Application through normal use. Your User Data also includes copies of the files that comprise LethargicOS, which you are free to modify as you wish. User Data might contain Personal Information only if you actively choose to store such information in LethargicOS.

The Web Application stores all of your User Data on your own local device. The server does not receive or store any User Data. The server is read-only to users and does not accept any uploads, and does not accept any HTTP requests that transmit data. Because your User Data does not leave your device, you are always in control of your User Data and what happens to it.

I (the author of this software) have no access to your User Data, which remains in your control at all times. I pledge to never alter the software to grant me access to anyone's User Data.

You can remove all of your User Data from the Web Application at any time, by clearing your browser's storage for this site using your browser's built-in functionality for doing so.

Logging

The server maintains an HTTP Error Log. If a web request should generate an error on the server, a log entry is generated and stored by the server. These logs are collected only for the limited and legitimate purposes of detecting and preventing fraud and unauthorized system access, ensuring the security of the server, and debugging software issues should they arise.

The server does NOT maintain an HTTP Access Log. Normal web requests (that do not result in server errors) are not logged, and leave no traces on the server.

HTTP Error Log entries are generated by the server and contain only metadata, and so are not considered to be part of your User Data as defined above. However, due to the presence of identifying information (specifically, your IP address), HTTP logs are considered to be Personal Information under GDPR. HTTP Error Logs are automatically deleted after 7 days. Additionally, under Article 17 of the GDPR, individuals have the right to have personal data erased. Requests may be sent to: webmaster@lethargiclion.net

Server logs will never be used for analytics, and will never be accessed by or transmitted to any third party.

Tracking and Analytics

This site does NOT track you in any way. There are no cookies. None of the code that I write for this site will ever track or attempt to identify this site's users. I do not perform any analytics anywhere, not even on my HTTP Request Logs. I do not knowingly include any tracking code in this site when it runs in your browser.

Please be aware that this Web Application deliberately provides you with the ability to execute arbitrary code within it, and I cannot control the behaviour of any third-party code which you might add and execute as part of your User Data.

I cannot send or offer any User Data to any third parties of any kind, because I have no access to it.

Warnings and Disclaimers

Disclaimer of Warranty and Limitation of Liability

The Disclaimer of Warranty and Limitation of Liability clauses apply. These are found as conditions within the Software License, which is posted at the top of this page.

Access and Availability

There is no guarantee of availability. This thing is experimental, and the server it runs on might go down, or I might update the code and accidentally break it. Even though the Web Application is intended to work without a server connection, I cannot guarantee that offline access will work as designed.

I reserve the right to terminate your access to my server for any reason by blocking or rejecting your requests. The Web Application is designed to function without a server connection, so in such an event, you will likely find that you are still able to use the Web Application in your browser, and your User Data will remain accessible to you.

Third-Party Code

This site includes and uses some third-party code in the form of open-source libraries. These libraries will be credited to their authors in accordance with their open-source licences.

To the best of my knowledge, none of the third-party code that is included in this site is performing any kind of tracking. However, mistakes do happen. If you find code that is included in this site which is performing tracking, please let me know so I can remove it, by emailing: webmaster@lethargiclion.net

This site is designed to function like a computer operating system: that is, it is a platform upon which executable code can be run in the form of applications. You are permitted (and encouraged) to run any code you want to on this platform, including code written by yourself or by third parties. However, I cannot be responsible for the actions of any code that you run which was not originally included. Please use common sense, and treat this site like your own computer: don't run things you don't trust!

Third-Party Websites

This site has the ability to embed windows which load other websites (like a browser within your browser). Any data you supply to an embedded website will be governed by the terms and privacy policy of that website. I do not and cannot control what third-party websites do with data that you provide to them.

Miscellaneous / FAQ

Why doesn't Incognito Mode/Private Browsing work?

The Firefox “private browsing” and Chrome “incognito” modes, by design, never store anything in the browser. However, this whole site is built on the concept of storing everything in your browser. Therefore, this site is fundamentally incompatible with those modes.

Was AI used to write or help develop this?

Fuck no. Fuck AI.

All of the code here was written by me, every line of it. Yeah, there were a few times when I got completely stuck on something, and in a moment of weakness I asked the Google Search AI for some suggestions. But then and now, I WILL NEVER copy and paste any AI-generated code into this project, nor will I use AI-enhanced development tools. I enjoy writing code, I enjoy coming up with my own solutions, and I like knowing exactly how every bit of my code works. But most of all, I have standards.

Also, this project is so fucking insane that I don't think any AI could correctly process whatever the fuck I'm doing in here.