You do not need to purchase a license in order to use Agar in commercial applications and we do not require any kind of compensation, but we hope that you will subscribe to our support service:
General discussion of Agar development and issues related to any of the libraries included in the Agar distribution. Plaintext posts only.
Automated notifications of changes made to the Agar source code repository (the Subversion repository is accessible here).
Other support channels