SoftMaker - Word and Excel Compatible - Already Portable!
Just to say that I'm a satisfied user of TextMaker (WP) and PlanMaker (Spreadsheet) from Softmaker.
These are non-free, but inexpensive (69 USD or 69 EUR for both apps on WIN32 AND Linux), and IMO excellent.
They are relatively small (about 35Mb for both), and already portable with a simple installation routine described here:
http://www.softmaker.com/english/tipsof_en.htm
No financial link, just a satisfied user. Well worth paying for.