I recently purchased a new iMac 27inch OS X El Capitan computer. I am a PhotoShop user and want to install an older Mac version of PhotoShop onto my new iMac. The PS operating system is OS X Leopard. Will it be compatible running on my El Capitan?
Welcome to the forums.
According to the "Roaring Apps" site Photoshop CS3 is compatible with El Capitan. And by the way, there is no such thing as a PS operating system. You have Photoshop CS3 and that is the way you should refer to it as. And please do not double post or cross post your question. We removed the duplicate.