Playground
Matra ships nothing by default. Tick an extension and it joins the document on the right · untick it and both the button and the behaviour go. The kilobytes are measured, and so are the milliseconds.
The figure on each one is what it adds to the bundle, gzipped.
Everything here is a real Matra document. Select a few words and use the toolbar, or type / if you have ticked the slash menu.
Tick an extension and this editor is rebuilt around it
Untick it and the button goes with it
The array is the feature list. Press Enter twice here to leave the quote.
The numbers above are measured, not quoted.