AlgoSim is released as freeware, and you do not have to pay the developer (or anyone) anything in order to use, copy, and distribute the software. However, if you like the software, you are allowed to donate an arbitrary amount (such as 160 SEK (Swedish kronor) which is about 20 USD) of money to the developer. You can donate by using the "Donate" button below. The donation service is managed by the high-security PayPal system. You can use your credit card (Visa, MasterCard, etc.) to pay.