Xerobank

xB Browser was previously called Torpark, and is released under a license that restricts usage by malware and commercial interests. xB Browser was originally forked from Portable Firefox web browser with Tor access built into it, but was redesigned from scratch in 2007.

It is designed for use on portable media such as a USB flash drive but it can also be used on any hard disk drive. As such, a secure and encrypted connection to any of the Tor or XeroBank routers can be created from any computer with a suitable internet connection, and the browser clears all data that was created on the portable drive upon exit or on demand.

XB Machine 0.2 RC1

This does not naturally provide anonymity for other Internet programs, only the xB Browser. However, other applications data such as Pidgin can be routed through the Tor network via xB Browser by directing the applications traffic to a SOCKS proxy at localhost, port 9050.

This port can be changed via xB Config, an INI generator for xB Browser located in its App/ directory. For a more complete explanation of the functioning of the system, see Tor.
Reading the Tor documentation is highly recommended to prevent configuration mistakes that could compromise the user's anonymity.

xB Browser is preconfigured, and the settings, especially within the browser, should not be modified unless done by an expert familiar with onion routing, and the workings of xB Browser itself.
XeroBank network
xB Browser is optimized for use on the XeroBank anonymity network, which is a private and commercial broadband network operated by Xero Networks AG. A cross-compatible version is being developed based on xB Machine, due to be available in August of 2008.
License
xB Browser is released under the Torrify Ethical Software License Agreement, or TESLA for short.

This type of license states that private use is unlimited, like GPL.