Visual languages mediate human and computer interaction. For some visual languages this mediation is straightforward; using a mouse to access a drop-down menu is well-known to computer users. For others, this mediation can be enriched via sketch and gesture recognition. This is made possible by advances in commodity hardware. More formal visual languages allow experts to accurately specify complex systems, such as software architecture or chemical molecules. A visual language can also encompass complex human-computer interaction such as navigating a set of semantically linked videos. Indeed, precision of semantics underlies visual languages and computation. Aspects of visual computing are multi-faceted in goals that are to be achieved during information or language design. The following represents a short list of qualities that are of importance to the study within visual computing: efficiency, aesthetics, pleasure, emotion, engagement, immersion, collaboration, and culture. Aspects of art, engineering, and science play key roles where certain practitioners focus on design and engineering of visual interactions whereas others analyze and study these interactions (i.e., science). The International Workshop on Visual Languages and Computing will explore these issues, and will be held in conjunction with the 2013 International Conference of Distributed Multimedia Systems (http://www.ksi.edu/seke/dms13.html). For this year's special theme we request high-quality submissions on visual languages that increase the efficacy of various tasks, or on the effectiveness of visual languages themselves. In addition to the special theme, we continue to solicit papers on all aspects and approaches to visual languages and computing, including interactive visual computing, computer-empowered visual computing, human-empowered visual computing, transformation algorithms for visual computing, and visual languages for visual computing.