It's good easy to learn to use for MEP Drawings Brics CAD can use Cad & BIM extension file DWG # Philemon _Dubai
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
SketchUp - 3D for Everyone
FreeCAD - An open-source parametric 3D modeler
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
nanoCAD - nanoCAD is a pro-grade 2D CAD system with native DWG support and full customizability.
SolidWorks - Dassault Systèmes SolidWorks Corp. develops and markets 3D CAD design software, analysis software, and product data management software. SolidWorks is the leading supplier of 3D CAD product design engineering software.