A few weeks ago after I wrote about Browzar (see the article at the URL below), a few people wrote to criticize the tool. That's to be expected, and I do respect their opinions even though they differ from mine. Since then, I've been looking around for other browsers that can help protect privacy above and beyond the typical browser features of being able to manually clear history and cache data. So far I've found two tools that fit the bill.
The first tool, PortableApps.com's Mozilla Firefox - Portable Edition (at the URL below) is based on Mozilla Foundation's Firefox code but was independently developed by John T. Haller. First released in June 2004, Firefox Portable seems to be kept up to date, including the addition of any necessary security fixes soon after vulnerabilities are found.
Firefox Portable is designed specifically to be copied onto portable media. You can install it on a small USB flash drive (or CD-ROM) and use it on nearly any PC that doesn't have its USB ports or CD-ROM drive locked down. Like regular Firefox, the portable version lets you install extensions and themes, but unlike Firefox, Firefox Portable helps prevent storage of usage information. Your download history is deleted when you shut the browser down cleanly (but not, for example, when you terminate the FirefoxPortable.exe process manually), URL history and form data storage are disabled by default, and no disk cache is used by default. However, you can configure Firefox Portable to write such data to the portable media (if the media is writeable) and use cache if you like.
I tested Firefox Portable, and it works just fine. The self-extracting executable dumps all the required files into one directory tree that you select. The installed size is about 16.5MB. Note that Firefox Portable won't run if another instance of Firefox is already running.
The second tool I found is Torpark (at the URL below). Developed by Hacktivismo, which "\[operates\] under the aegis of the \[infamous\] Cult of the Dead Cow (cDc)," Torpark is relatively new and based on the Firefox Portable code. It includes a very interesting added benefit in that it uses the The Onion Router (Tor) network.
In case you aren't aware of it, Tor (at the URL below) is software that builds a network of relatively anonymous servers by chaining them together automatically to encrypt and route traffic to and from its destination. At its core, a Tor client acts as a Sockets (Socks) proxy.
According to the developers, "Torpark comes pre-configured, requires no installation, can run off a USB memory stick, and leaves no tracks behind in the browser or computer." Sounds pretty good, right? There is however one drawback: Tor can be very slow at times. Tor volunteer server operators can regulate how much bandwidth they devote to their Tor server, and it seems that many Tor server operators allocate only a small amount. But if you really need anonymous Web surfing ability, some lag time is probably worth it.
I tested Torpark and it's really easy to use. The installation process is the same as for Portable Firefox except that Torpark also installs the Tor client. The installed size is about 27MB. The custom Web interface includes all the regular Firefox controls along with two additional buttons: one to enable or disable use of the Tor network (so you can use Torpark without Tor to just browse without encryption) and another to flush the Tor circuit. The latter feature causes Tor to chain together a new set of Tor servers to use as your path out to the Internet. Flushing the circuit doesn't always result in a faster circuit, but at times it might, so the feature is helpful.
I'll also point out for the Browzar detractors that neither Firefox Portable nor Torpark include any spyware or adware. Both let you customize the search tool just like Firefox does.