We discuss the organization of an experimental economics laboratory, and the use of experimental software tools. We distinguish between “software tools” like z-Tree, oTree, PHP and JavaScript and “programs,” which are the actual programs (scripts) containing the logic of the experiment. First, we review the broader topic of laboratory organization and the (re-)use of programs (and protocols), focusing on the need for clear rules, the centrality of a logbook, and the availability of a central repository for programs and protocols. Then we review criteria to select software tools, discussing technical criteria like adaptability, and scalability, but also non-technical criteria like the usefulness of certain programming skills for PhDs leaving academia. Finally, we apply these criteria on three of the available software tools: o-Tree, z-Tree and standard internet programming tools, like PHP and JavaScript.