z-Tree (Zurich Toolbox for Readymade Economic Experiments) is a software for experimental economics. This software package allows to develop and to carry out economic experiments. In this program features that are needed in most experiments are generally defined. Among them are the communication between the computers, data saving, time display, profit calculation and tools for screen layout. A further strength of the program lies in the versatility: It can be used for a wide range of possible experiments such as public good experiments, structured bargaining experiments or markets - including double auctions and Dutch auctions. Moreover, experiments can easily be composed and combined.

Another feature of the program is its user-friendliness. Experimenters without programming knowledge can also use it. New experiments can be developed with low marginal effort. A public good experiment, for instance, can be programmed within an hour, a double auction within a day. After some experience, developing a new experiment does not take much more time than to write the instructions.