Apache 2.0 offers numerous enhancements, improvements and performance boosts over the 1.3 codebase. The most visible and noteworthy addition is the ability to run Apache in a hybrid thread/process mode on any platform that supports both threads and processes. This has shown to improve the scalability of the Apache HTTP Server significantly in our testing. Apache 2.0 also includes support for filtered I/O. This allows modules to modify the output of other modules before it is sent to the client. There is also support for IPv6 on any platform that supports IPv6. This version of Apache is known to work on many versions of Unix, BeOS, OS/2, Windows, and Netware.