High throughput experimentation (HTE) in catalysis re-search and materials science has ± in spite of its relativelyshort history ± already reached an impressive level ofsophistication with respect to synthetic methods [1], reactortechnology [2], and fast analytical assays [3], and severalreviewpapersareavailablewhichcoverthesedevelopments[4]. In order to fully exploit the advantages associated withthe success in the above mentioned areas, equally sophis-ticatedmethodsarerequiredtomanagetheflowofdataandto extract useful information from these data. However,suitable solutions to these problems, often even partialsolutions, are still lacking. Fully integrated and adaptedinformatics tools to capture, store and treat the highthroughput workflow of data for heterogeneous catalysisand materials are yet to be developed. Equally important,efficient software based methods for library design, forwhich developments on the fundamental level are stillnecessary, are urgently needed to make full use of the novelexperimental tools.Some of the problems are similar as in high throughputdrug discovery, where advanced software support solutionsfollowed the experimental developments. However, thehigh complexity of solids and heterogeneously catalyzedprocessescreatesnovelchallengesgoingbeyondthosefacedin drug discovery. These challenges are often not acknowl-edged, yet, in the community. In this essay we will point outoften-underestimated fundamental differences betweendrug discovery and materials science, which are faced insoftware assisted library design for high throughput ap-proaches. Even if HTE increases the screening power byorders of magnitude, the number of potential experimentsto be carried out is infinite (see, for example, the consid-erations of Jansen concerning the number of possible solidcompounds [5]). Therefore new methodologies have to bedeveloped which allow the design of efficient libraries.Novelconcepts andstrategies for screening with specializedsoftware components are proposed to enhance discoveryand optimization rates.HTE in heterogeneous catalysis and materials sciencerelies on the iterative preparation and testing of largelibraries of solids, either in a parallel mode or sequentially.Theprocessstartswiththedesignofaninitialsetofcatalysts,which can be done either randomly, or following certainrules, or be based on the experience and intuition of thechemist who designs the library. Such an initial library isthen prepared and tested. After analyzing the results andbased on the analysis, a new set of experiments is designed.This methodology is not fundamentally different from theone used in the past in the search for novel catalysts andprocesses. However, the role of the chemist drasticallychanges because the numbers of experiments to be con-ducted and the amount of data to be collected and treatedare orders of magnitude higher. Without an efficientinformatics environment, it is impossible to plan and designsuch vast numbers of experiments [6].In the beginning of a high throughput discovery programtwo possible starting situations can be identified:(i) screen-ing is based on prior information and catalytic systems areavailable which show some activity for the desired reaction,or (ii) there is essentially no precedence of a catalyst, or thesystems previously investigated do not seem to have thepotential for further improvement. The first situation isoften described by the term ™optimization program∫, thesecond situation subsumed under the label ™discoveryprogram∫.