nternet has increased its capacities and possibilities exponentially since its inception. This evolution has been possible because of new standards and technologies, like Web services. Structural analysis software has benefited from the Web supplying a new set of applications that provide highly intensive computational tasks in Web servers. However, recent and future improvements in the Internet will enable the development of a new type of structural analysis application fully integrated in Web browsers and not only deployed as Web services. This type of Internet application is formally known as a Web application. This paper presents the development of a 3D Web application for structural analysis, known as Structural Analysis Software as a Service, which is applied to 3D lattice girder structures. The latest cutting-edge Internet technologies are used to address fundamental issues inherent to structural analysis software such as visualization, interaction, and structural analysis. Specifically, WebGL API, part of the new HTML5 standard, is used to solve the visualization and interaction issues of the proposed application. This prototype only requires an Internet connection and an updated browser that supports these new standards. No additional plug-in or virtual machine interpreter is needed; thus, platform independence is guaranteed. DOI: 10.1061/(ASCE)CP.1943-5487.0000217. (C) 2013 American Society of Civil Engineers.