Relevant entries from around TPFC forums:
- Vidiot (portable, viewtopic.php?t=20911)
- OpenShot (PAF, viewtopic.php?ft=23000)
- Shotcut (non-portable, viewtopic.php?t=20910)
- Kdenlive (non-portable, viewtopic.php?t=23257)
Video editing tools from TPFC's database:
- VirtualDub Portable (http://www.portablefreeware.com/?id=19)
- MKVcleaver (http://www.portablefreeware.com/?id=2039)
- Mpg2Cut2 (http://www.portablefreeware.com/?id=2404)
- X-Avidemux (http://www.portablefreeware.com/?id=2373)
Related other untested freeware:
- Jahshaka (http://www.jahshaka.com/)
- ZS4 Video Editor (http://www.zs4.net/ [Dead?]; Softpedia)
- Natron (portable? https://natrongithub.github.io/)
Of course this preliminary list must mention a tool that's both free and portable, but works only in command line mode:
- FFmpeg (viewtopic.php?t=16912)
Finally, a note that I once nurtured high hopes for VLMC (http://www.videolan.org/vlmc/), a VLC associated editor, but the project seems to have gone nowhere.
So that's it for now.