The wiki concept

https://www.kiwix.org

Allows you to keep a complete copy of Wikipedia and hundreds of websites on your phone or computer.
After installation, it works like a regular site, with all the links.
Free and without ads.

Contains

• Wikipedia (including smaller topic collections such as football or math) in more than 100 languages.,
• Wiktionary,
• TED talks

https://en.wikipedia.org

Open World Encyclopedia, compiled by all Internet users in all languages of the world.
Anyone can become a co-author of this encyclopedia.
You can create a new section, a new article, a note, fix an error in an existing one, add something, comment, etc.
In general, you are a full-fledged creator of this vast knowledge base.

A wiki is a hypertext environment (usually a Web site) for collecting and structuring written information. Characterized by the following features:

• A lot of authors. Some wikis can be edited by all visitors.
• The ability to repeatedly edit the text through the wiki itself (the website), without the use of special tools on the editor's side.
• Manifest changes immediately after they are made.
• Separation of information into pages where each has its own name.
• A special markup language that allows you to quickly and easily mark out structural elements, formatting, hyperlinks, etc. in the text.
• Change accounting (version accounting) of the text and the ability to roll back to the earlier version.

https://fallingfruit.org

A map of the harvest in the city.

On the map are marked fruit trees or bushes where you can pick fruit for free.
Usually in the city such trees grow for decorative purposes and eating from them is not forbidden.
It is not quite clear who and how collects the base. But there is one such tree in St. Petersburg and it is called the BEREZA (BIRCH).

https://trashwiki.org

Points where chain stores or markets throw food still usable.

https://www.wikihow.com

How to do anything? This is what this VIKI site does, or rather what we all do, well, if WIKI does.
Open source project with open content.

The online community collects a database of practical manuals and instructions on how to do it.

The goal is to build or create the largest base.

Over 35.5 million unique visitors.
Over 190,000 free reference articles.
Over 1,600,000 registered users.

Free encyclopedia of programming languages.
The idea of the project is to compile the most complete list of programming languages (along with dialects, implementations and versions), structure information about them and give each language an example of solving several standardized tasks.