Privoxy 3.0.13 introduces IPv6 support, improved keep-alive support and a bunch of minor improvements:
Added IPv6 support. Thanks to Petr Pisar who not only provided the initial patch but also helped a lot with the integration.
Added client-side keep-alive support. This should also allow NTLM authentication through Privoxy, but this hasn't been confirmed yet.
The connection sharing code is only used if the connection-sharing option is enabled.
The max-client-connections option has been added to restrict the number of client connections below a value enforced by the operating system.
Fixed a regression reintroduced in 3.0.12 that could cause crashes on mingw32 if header date randomization was enabled.
Compressed content with extra fields couldn't be decompressed and would get passed to the client unfiltered. This problem has only be detected through statical analysis with clang as nobody seems to be using extra fields anyway.
If the server resets the Connection after sending only the headers Privoxy forwards what it got to the client. Previously Privoxy would deliver an error message instead.
Error messages in case of connection timeouts use the right HTTP status code.
If spawning a child to handle a request fails, the client gets an error message and Privoxy continues to listen for new requests right away.
The error messages in case of server-connection timeouts or prematurely closed server connections are now template-based.
If zlib support isn't compiled in, Privoxy no longer tries to filter compressed content unless explicitly asked to do so.
In case of connections that are denied based on ACL directives, the memory used for the client IP is no longer leaked.
Fixed another small memory leak if the client request times out while waiting for client headers other than the request line.
The client socket is kept open until the server socket has been marked as unused. This should increase the chances that the still-open connection will be reused for the client's next request to the same destination. Note that this only matters if connection-sharing is enabled.
A TODO list has been added to the source tarballs to give potential volunteers a better idea of what the current goals are. Donations are still welcome too: http://www.privoxy.org/faq/general.html#DONATE
A quick list of things to be aware of before upgrading from earlier versions of Privoxy:
The recommended way to upgrade Privoxy is to backup your old configuration files, install the new ones, verify that Privoxy is working correctly and finally merge back your changes using diff and maybe patch.
There are a number of new features in each Privoxy release and most of them have to be explicitly enabled in the configuration files. Old configuration files obviously don't do that and due to syntax changes using old configuration files with a new Privoxy isn't always possible anyway.
Note that some installers remove earlier versions completely, including configuration files, therefore you should really save any important configuration files!
On the other hand, other installers don't overwrite existing configuration files, thinking you will want to do that yourself.
standard.action has been merged into the default.action file.
In the default configuration only fatal errors are logged now. You can change that in the debug section of the configuration file. You may also want to enable more verbose logging until you verified that the new Privoxy version is working as expected.
Three other config file settings are now off by default: enable-remote-toggle, enable-remote-http-toggle, and enable-edit-actions. If you use or want these, you will need to explicitly enable them, and be aware of the security issues involved.