The International Colloquium on Theoretical Aspects of Computing (ICTAC) was founded in 2004. In 2014, the eleventh edition of ICTAC is organized for the first time in Europe, namely in Bucharest, Romania. Since its early days, the study of computer science in Romania has had a strong theoretical component, owing in part to the mathematical orientation of some of its most notable pioneers, such as Professor Grigore Moisil. In modern times, this legacy is proudly carried on by several prestigious research institutions, such as the University of Bucharest and the Romanian Academy. A burgeoning metropolis in recent years, Bucharest is a lively, cosmopolitan city. Featuring an eclectic mix of architectural styles and traditions, cultural and artistic life, Bucharest is an ideal setting for the 11th International Colloquium on Theoretical Aspects of Computing. The Colloquium aims to bring together practitioners and researchers from academia, industry and government, with the purpose of encouraging the presentation of novel research directions, through the exchange of both ideas and experience, related to current theoretical challenges in computing, as well as practical applications of existing theoretical results. An additional goal is that of promoting wide-reaching forms of cooperation in research and education between participants and their institutions, from developing and industrial countries. We are honored to have three distinguished guests as invited speakers: Cristian Calude (University of Auckland, New Zealand), Jin-Song Dong (National University of Singapore, Singapore), and Razvan Diaconescu (Institute of Mathematics of the Romanian Academy, Bucharest). Professor Solomon Marcus will be a special guest, providing a talk on important differences and similarities between Theoretical Computer Science project and the Bourbaki project in Mathematics. Professor Cristian Calude will present a talk entitled\textit{ Probabilistic solutions to undecidable problems} which addresses the (in)famous algorithmically undecidable halting problem. Undecidability is everywhere: in logic, mathematics, computer science, engineering, physics, \ldots ; the talk reveals how a probabilistic method can help deal with undecidable problems. Professor Jin-Son Dong will present a talk entitled \textit{Event Analytics} in which he will describe the Process Analysis Toolkit and his vision of \textit{event analytics}, which goes beyond \textit{data analytics}. The event analytics research is based on applying model checking to event planning, scheduling, prediction, strategy analysis and decision making. Professor Razvan Diaconescu will present a talk entitled \textit{From Universal Logic to Computer Science, and Back}, focusing on universal logic. He will recall some important ideas that have shaped the success of institutional model theory in computer science. Moreover, he shows how insights from computer science have led (through institutional model theory theory) to a (sometimes drastic) reformulation and novel understanding of several important concepts in logic, resulting in a set of new and important results.