The requirement is on the part of the web browser. Modern web browsers, such as Firefox, Chrome and Safari, can render mermaid. But Internet Explorer cannot. The web browser also needs access to the online mermaid renderer which it downloads from https://cdn.jsdelivr.net/npm/mermaid
The `Mermaid configuration` is for controlling mermaid behaviour. An easy introduction to mermaid configuration is found in the [Advanced usage](n00b-advanced.md) section. A complete configuration reference cataloguing default values is found on the [mermaidAPI](mermaidAPI.md) page.
Thanks to the growing popularity of mermaid, many plugins already exist which incorporate a mermaid renderer.
One example is the [Atlassian Confluence mermaid plugin](https://marketplace.atlassian.com/apps/1214124/mermaid-plugin-for-confluence?hosting=server&tab=overview)
When the mermaid plugin is installed on a Confluence server, one can insert a mermaid object into any Confluence page.
We do not need to install anything on the server, apart from a normal file of html to be reached by a web browser (such as Firefox, Chrome, Safari, but not Internet Explorer). So if you want to really simplify things when testing this out, don't use a web server at all but just create the file locally and drag it into your browser window. It is the browser which does all the work of rendering mermaid!
3. When initializing mermaid using `mermaid.initialize()`, mermaid takes all the `<div class="mermaid">` tags it can find in the html body and starts to render them one by one. This is done like so:
- In early versions of mermaid, the `<script src>` tag was invoked in the `<head>` part of the web page. Nowdays we can place it directly in `<body>` as seen above. However, older parts of the documentation frequently reflects the previous way which still works.
- We initialize the mermaid rendering with `mermaid.initialize()` directly in the html code. In principle this could be done through placing `mermaid.initialize()` inside of `mermaid.min.js`. We would then eliminate the need for this explicit line in the html. However, there are use cases where we do want to separate the two steps. Sometimes we want full control over when we start looking for `<div>`tags inside the web page with `mermaid.initialize()`, for example when we think that all `<div>` tags may not have been loaded by the time `mermaid.min.js` runs.
- In the example above, `mermaid.min.js` is called using an absolute path. Even worse, the example includes the mermaid version number which of course will change as time goes by. However, the example makes it easy to understand what is going on - even though it is perhaps doomed in a way we do not want in a production environment. When going from testing mermaid out to getting serious with it, I would suggest one of the following approaches for calling `mermaid.min.js`:
1. If you do not enter a specific version, you automatically get the latest one.
2. If you really need a specific version, hard code it (this is rare but it happens).
3. If you need to know the current mermaid version, replace a mermaid code block with the word `info` and the version will be returned. Like [this](https://mermaid-js.github.io/mermaid-live-editor/#/edit/eyJjb2RlIjoiaW5mb1xuXG4iLCJtZXJtYWlkIjp7InRoZW1lIjoiZGVmYXVsdCJ9fQ==)
