Licensing
Versions of AddyScript prior to 0.9.9 were published under the GNU Lesser General Public License (LGPL). The source-code was then shared on CodePlex (now archived).
Since version 0.9.9, AddyScript is licensed under the MIT License.
This essentially means that you are still free to use or modify AddyScript in any project, whether it is commercial or not, open-source or not, at no cost without being obliged to provide your source-code.
However I would be very pleased if you mention in your project (or one of its relative content) that part (or the whole) of your work derives from AddyScript.