Dual-engine (IE/Trident and Gecko/Mozilla), closed-source freeware with lots of extra goodies.
Avant seems to have gone tri-engine by adding webkit:
Avant Browser 2012 build 173, Released 6.14.2012
[Update] Firefox rendering engine (22.214.171.12445)
[Update] Chrome rendering engine (19.0.1084.56)
[Fix][Gecko] Firefox.exe crashing problem aftering enabling silverlight
[Fix][Webkit] For the same link, Avant Downloader can't pop up twice after canceling the first task.
[Fix][Webkit] Searching via Address Bar failed.
[Fix][Trident] Saving AutoFill dialog automatically popped up when loading a page
[Fix] Avant Downloader can't detect videos on certain sites
[Fix] The video on the page sometimes played in the background after clicking the full screen button on the video player.
: what's preventing Avant
's USB version from being stealth, if you don't mind my asking?