Pale Moon Portable is a Stand Alone Web Browser created by Moonchild Productions. This Portable Browser is based on a minimalist Firefox framework, but is entirely optimized for modern chipsets.
SRWare Iron is a Portable Web Browser based on the extremely fast Google Chrome Browser (Chromium) source code. It is essentially the same, with a singular focus on user privacy.
K-Meleon is an open source portable web browser that can be taken with you to run from USB. Based on the Gecko Engine created and used by Mozilla Firefox, this browser is lightweight and extremely fast.