Completely legal, open-source, and free from malware. 3. ONLYOFFICE Desktop Editors (Portable)

| Feature | Office 2007 Portable (100 MB) | LibreOffice Portable (300 MB) | Office 365 Web (0 MB, needs internet) | | :--- | :--- | :--- | :--- | | | 100 MB (Winner) | 300 MB | 0 MB | | Offline Access | Yes (Winner) | Yes | No | | Modern File Format (.docx) | Yes | Yes | Yes | | Cloud Collaboration | No | Limited | Yes (Winner) | | Speed on Old PC | Instant (Winner) | Slow (~15 sec load) | Not applicable (Browser slow) |

A legitimate "portable" application is a program configured to run entirely from a single folder—often on a USB flash drive—without writing to the Windows Registry or leaving configuration footprints on the host computer.

The result is a . This means:

Instead of bundling hundreds of custom fonts, the package is configured to rely strictly on the host operating system's native font directory.

Full capability to manage fonts, paragraph alignment, margins, and headers.