If the legal gray area worries you, consider these truly portable CAD tools:
Always run downloaded executables through an updated antivirus scanner or a service like VirusTotal before execution. zwcad portable - The House of Portable
If you need flexibility, ZWSOFT offers official methods for "portable" use: ZWCAD Mobile : Allows viewing and editing files on-the-go with cloud syncing and secure encryption. Network Licensing : The official software supports Network Licenses If the legal gray area worries you, consider