There are many new features in Privoxy 3.0.4 :
Mulitiple filter files can now be specifed in config.
There are a number of new actions:
MS-Windows versions can now be installed and started as a service.
In addition, there are various bug fixes and enhancements, including error pages are no longer cached, better DNS error handling, and logging improvements.
A quick list of things to be aware of before upgrading from earlier versions of Privoxy:
Some installers may remove earlier versions completely, including configuration files. Save any important configuration files!
What constitutes a "default" configuration has changed, and you may want to review which actions are "on" by default. This is primarily a matter of emphasis, but some features you may have been used to, may now be "off" by default.
Some installers may not automatically start Privoxy after installation.