The Insert Anchor plugin version "2.0" allows the user to add and edit Anchors.
To create a link to an anchor just use the insert-link button and enter "#anchorname" as url.
The origin Insert Anchor plugin version "1.0" was developed by Andre Rabold and is under htmlArea license.
This version of Insert Anchor allows the user to add anchors in the page. However you can not edit them.