In our prototype implementation, we did not mainly focus on the runtime performance
of the proxy server itself (although it was very sufficient) - after the solution
turns out to be stable we plan to implement caching functionality,
which should fairly reduce performance costs.
The HTML-tidying process costs a mentionable amount of time (only tested with JTidy),
while XSL- and XQuery-processing is usually quite fast.
A detailed analysis regarding the proxy server's performance, including
a comparison between different HTML-pretty-printers and stylesheet-processors
will be presented in the future - together with the implementation of the caching functionality
(see section 4.4.2).