1. FreeCAD: A free and open-source 3D CAD software.
2. DraftSight: A free CAD software with a familiar interface.
3. SketchUp: A popular 3D modeling software.

Finding a reliable link for a "portable" version of AutoCAD 2012 is difficult because Autodesk does not officially release portable versions of its software autocad portable 2012 64 link

• Specific Visual C++ redistributables
• .NET Framework components
• Registry entries for licensing and file associations
• System services like FlexNet for license management

If you need to use AutoCAD without a traditional local installation or are looking for older versions, consider these official paths: Autodesk does not officially release or support "portable"

• Give step-by-step instructions to download and install a licensed AutoCAD from Autodesk.
• Suggest compatible free/open-source alternatives based on your needs (2D vs 3D, DWG editing, system requirements).
• Help convert files or find a workflow to open old DWG files in modern software.

1. Convenience: The portable version allows users to carry the software on a USB drive or other portable storage device, making it easy to use on multiple computers.
2. Flexibility: The portable version can be used on any 64-bit Windows computer, without the need for installation or administrative privileges.
3. Cost-effective: The portable version can be a cost-effective solution for users who need to use AutoCAD on multiple computers, but do not want to purchase multiple licenses.