Question: What is a Journaling file system?

Even wikipedia doesn't give much information. Apart from NTFS which other file systems(on Windows / Linux) support journaling and how does it give a performance boost?

Answer: 
A journaling filesystem records changes to the filesystem before it actually performs them. In this way it is able to recover after a failure (e.g. power fail) with minimal loss of data.

The [Features](http://en.wikipedia.org/wiki/Comparison_of_file_systems#Features) section of Wikipedia's comparison of filesystems gives which are journaled.

Journaling does not give a performance boost. In fact, the journaling operationn reduces the speed slightly, in exchange for the above reliability.
The wikipedia article on [Journaling file system](http://en.wikipedia.org/wiki/Journaling_file_system) contains a lot more details on what it is, how it works, and why.