This volume contains twenty-five outstanding papers from leading experts in the field that aim to inspire, provoke, and educate present and future generations of computational chemists and to prepare them for the challenges of the 21st century. This special edition of selected papers from the Journal of Molecular Modeling - the first electronic online journal in the history of science - is devoted to the event of Paul von Ragué Schleyer's 75th birthday. The contributors to this issue, among others the nobel laureate G.A. Olah, come from many different phases of the career of Paul von Ragué Schleyer, one of the most remarkable and innovative chemists of the 20th and 21st centuries. The papers demonstrate the progress of computational chemistry since the last volume was published five years ago and underline the contributions that the Schleyer school has made to many branches of science. The volume will be used as an extremely useful source for computational, theoretical and physical chemists in industrial research and academia. Readers receive free online access to the electronic supplementary material of the respective papers.