Strucsoft Inc. - Plant design software for mechanical, structural, instrumentation and electrical design. - http://www.strucsoft.ca/
AEC Design Group - Develops and distributes AutoCAD-based software for the process plant and building services industries worldwide. - http://www.cadpipe.com/
PRO-CAD Software Ltd. - Developers of 2D Designer and 3D Smart piping and electrical drafting and design software add-on programs for AutoCAD. - http://www.procad-software.com/
Devpipe - An AutoCAD application for generating the intersection profiles between pipe elements of various shapes. - http://www.devpipe.com.br/
Satish Lele - A collection of AutoCAD add-on programs for piping in 2D and 3D, and other AutoLISP routines. - http://business.vsnl.com/nelcon/