PipeCAD can be used for Plant Piping Design, PipeCAD has the following functions:

• Grid Modeling;
• Equipment Modeling;
• Structure Modeling;
• Piping Modeling;
• Piping Isometric Drawing;
• Piping Draft Drawing;
• Piping MTO List;
• Customization by Python;

License

PipeCAD is not open sourcebut you can use PipeCAD Personal Edition for free.

PipeCAD provide customization by Python. The python plugins locate in the
PipeCAD/Lib/pipecad folder.
The Python plugins are open source with MIT license.

Download

Download PipeCAD from here: https://github.com/eryar/PipeCAD/releases

There is a Sample project in PipeCAD, You can use the user SYSTEM and password XXXXXX to login the Sample project.

There are some videos to illustrate how to use PipeCAD: https://space.bilibili.com/1548012589

IsoAlgo3d

3D WebGL Viewer for Piping PCF/IDF File: https://eryar.github.io/PipeCAD/