How do you make link!?

Where?

In the forums, do the following:
Replace “link” with your link and “text” with the text you want.

In comments and project instructions / notes / profile text boxes I think you can only link to Scratch sites, but all you have to do is paste the link in. It won't show for you, but if you sign out, it will appear as a link.

With comments you also just paste in the link.

You can also link to a user page (in everywhere but the forums) by putting the “@” sign then the username you are linking to. If the user exists, it will appear as a link.