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 a Free and Portable Web Browser that can be run portably from USB. Based on the Gecko Engine created and used by Mozilla Firefox, the Portable K-Meleon Web Browser is lightweight and extremely fast.