XMIND recently launched a new portable version of its open-source mind mapping software that can be downloaded in a single zip file – containing Mac, Windows, Linux 32-bit and Linux 64-bit versions – and used on any computer.
This appears to be the standard basic, open-source version of XMIND v3.0.3 – not a stripped down version. It also supports 5 languages: English, Simplified Chinese, Traditional Chinese, German and Japanese.
The good news is that the program files are small enough that you can easily copy them onto a USB key and carry both the programs and your maps everywhere. The program can be used without registering it online. Just install it and start mapping. The developer says that XMIND Pro is also available in a portable version.