From memory, the other popular domain name extensions were taken at the time.
Dharma Wheel (the Mahayana/Vajrayana one) is dharmawheel.net
If we had first dibs at all the domain names ever invented it would be easier... but in the absence of that, we have what we have. I think the complete absence of ads and paid memberships is sufficient to demonstrate that the site is not-for-profit.
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)