The simulations and associated resources on Biology Simulations are free for anyone to use. Advertising revenue (via AdSense) helps offset the cost of domain registration and web hosting. The time spent designing, developing, and maintaining the simulations and resources is compensated through donations.
If you’d like to support the time and skill that goes into Biology Simulations, consider making a donation via the Donate button (PayPal). Donations go to Jolene Pappas (see the About page for more information). While any individual donation is appreciated, teachers who use the simulations for classes are encouraged to ask their districts to make a donation.
Thank you for using Biology Simulations!