Neopets Toolbar Add-on requires that you accept the following End-User License Agreement before installation can proceed:
This extension is meant to work in conjunction with the official Neopets Toolbar, and not as a substitution. In cases where Neopets Toolbar works as it should, users MUST install the Neopets Toolbar before using this extension.
If Neopets Toolbar is not supported*, users are allowed to use this extension as a standalone until TNT/VSI releases a supported version. After which users MUST install the Neopets Toolbar.
This agreement is in place to protect the interest of Neopets Toolbar.
* Definition of "supported": Able to download and install from http://toolbar.neopets.com
directly. Most or all of the Neopets Toolbar features work in normal condition. Normal condition includes Neopets Toolbar clashes with other extensions (which in this case, users have to send a bug report to the respective extension support team/developer).