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--- a/docs/index.md
+++ b/docs/index.md
@@ -1,11 +1,34 @@
 # Getting Started
 
-## What is this?
+## What is this
 
 *txtdot* is a proxy that requests the page by the given URL,
-extracts only useful data (text, links, pictures, tables, etc.)
+extracts only useful data including text, links, pictures and tables,
 and returns it as an HTML page with a minimalistic design
-optimized for reading text.
+optimized for text reading.
 
-*txtdot* increases the loading speed and reducing client's bandwidth usage
+*txtdot* increases the loading speed and reduces client's bandwidth usage
 since no unnecessary code and no scripts are transfered.
+Also, you won't see any advertisement (unless it's a static picture that is hard to detect as ads).
+There are no trackers too.
+
+## How it works
+
+This project exists thanks to great Mozilla's
+[Readability.js](https://github.com/mozilla/readability) library.
+The initial idea was to process HTML with it on the server
+so the client does not need to download and execute heavy JS,
+doesn't need to use an adblock.
+
+Readability performs its work very well in most cases.
+But not always. For example, check any StackOverflow page or Google search results.
+
+So [artegoser](https://github.com/artegoser) wrote the basis of the code
+keeping in mind that we'll extend txtdot with other *engines*.
+For now, engines are functions taking a URL as a parameter,
+returning an object that contains extracted HTML and plain text, page title and language.
+The object is rendered with ejs template (or, in `/api/parse`, just sent as JSON).
+
+If a `?engine=` parameter wasn't passed, txtdot checks
+if the requested domain is assigned to a specific engine,
+for example, "stackoverflow.com" -> "stackoverflow".