This is the proceedings of the Third Workshop on Computing: Theory and Practice, WCTP 2013 devoted to theoretical and practical approaches to computation. This workshop was organized by four top universities in Japan and the Philippines: Tokyo Institute of Technology, Osaka University, University of the Philippines - Diliman, and De La Salle University. The proceedings provides a comprehensive view of the current development of fundamental research in formal method, programming language and programming development environment, bioinformatics, empathic and intelligent systems, and computing gaming in Japan and the Philippines.Contents:Call-by-Name Evaluation of RPC and RMI Calculi (S Araki and S Nishizaki)Notes in Delays and Bisimulations of Spiking Neural P Systems Using SNP Algebra (H N Adorna, K C Buño and F G C Cabarle)Probing the Hardness of the Approximate Gene Cluster Discovery Problem (AGP) (G S Cabunducan, J B Clemente, H N Adorna and R T Relator)Weak Bisimulation Between Two Biogeochemical Cycles (J B Clemente, H N Adorna and J J S Villar)A Simulation of Transition P Systems in Weighted Spiking Neural P Systems (R A B Juayong, N H S Hernandez, F G C Cabarle and H N Adorna)Robustness Analysis on Human-made Faults in Procedural Manuals (N Nagatou and T Watanabe)Compositional Construction of Group-wide Meta-level Architectures (T Watanabe)An Application Programming Interface for the Communication and Storage Protocol for the TALA Empathic Space (G Cu, J M R Cipriano, M J Gonzales, K M Tanalgo, C K B Magdaong, M P Tiu and J R U Longalong)An Object-oriented Language for Parameterised Reactive System Specification based on Linear Temporal Logic (K Osari, T Murooka, K Hagiwara, T Ando, M Shimakawa, S Ito, S Hagihara and N Yonezaki)Building Policies for Supportive Feedback in Self-Directed Learning Scenarios (P S Inventado, R Legaspi, K Moriyama, K Fukui and M Numao)Data Collection with Prioritization for Wireless Sensor Networks (A V Ong and G Cu)Health Information Search Personalization with Semantic Network User Model (I Puspitasari, K I Fukui, K Moriyama and M Numao)Learning English Words via Animations and Making Sentences Using an Etymological Memorization Method (K Sumi and A Kazuhara)A Serious Game Stimulating Children’s Interest in Chemical Bonding (K Sumi and K Kudo)Development of a Visual Debugger for C Implemented in JavaScript (A Nagae and K Kagawa)Flash Code with Dual Modes of Encoding (M J Tan, P Fernandez, N A Salazar, J Ty and Y Kaji)Ranking Analysis of Battle Result of Board Game Strategy in Java Programming Exercise (K Yamada and H Tominaga)Distributed Inference to Support Inter-Subjective Empathic Computing (M Numao)Readership: Graduate students and professionals in the field of artificial intelligence, software engineering/programming and computer science.