libapache2-mod-xsendfile | Serve large static files efficiently from web applications | Mehr ...
This package provides the xsendfile module for the Apache 2 webserver. xsendfile is a small Apache2 module that processes X-SENDFILE header sent by the original output handler. . If it encounters the presence of such header it will discard all output and send the file specified by that header instead using Apache internals including all optimizations like caching-headers and sendfile or mmap if configured. . It is useful for processing script-output of e.g. php, perl or any cgi.