Xdebug is a complicated piece of software, and has always been released under an Open Source license, and this will continue into the far future. It has cost me thousands of hours to develop, test and support Xdebug. If you find Xdebug valuable, I would appreciate it if you would consider having a look at my Amazon Wishlist. If you want to donate something smaller, than an Amazon Gift Certificate from the UK store (to derick@xdebug.org) is also very welcome. I can sadly not use gift cards from other amazon stores (.de, .fr, .com) as they don't work in the UK store.