Number Duck is dual licensed as Open Source (AGPLv3) and commercial closed source.

Comercial closed source licences and be purchased for $149 USD per developer, and include 12 months of updates.

Please send any purchase requests to adam@numberduck.com, noting how many licences are required, and I will send you a payable invoice via PayPal.

All purchases are covered by a 30 day money back guarantee, no questions asked. Just email me personally and I will sort it out for you. Also feel free to email me if you have any problems, questions or comments.