A pipeline project normally not only covers a large geographic range, but also deals with a variety of data sources, such as geological, geographical, environmental, engineering and socioeconomic data. GIS has proven to be the effective approach to integrating, managing and analyzing these heterogeneous data sources. Due to the nature of pipeline applications, the third dimension of geospatial data is of considerable importance for pipeline planning, construction and maintenance. There is an increasing demand for the development of a 3-D GIS for pipeline applications. With the advent of Internet, distributed computing and computer graphics technologies, development of web-based 3-D GIS becomes technologically possible. The combination of 3-D GIS and web-based computing technologies opens a whole new avenue to the pipeline industry. In this paper, we will address the development of a web-based 3D GIS in terms of benefits and technical challenges. The detailed system architecture as well as the algorithms developed is also discussed. Finally, potential applications for the pipeline industry are introduced and a prototype system, GeoEye 3D, developed by the Department of Geomatics Engineering at the University of Calgary is described.