<IfModule mod_deflate.c>  
#General Configuration settings: use ratio method and highest compression
DeflateFilterNote ratio
DeflateCompressionLevel 9

#Approach 1: Implicit ("Set") compression
## There are potential issues with compressing everything 
## It will for example send xml compressed to web services or flash
#SetOutputFilter DEFLATE
#SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.avi$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.mov$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.mp3$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.mp4$ no-gzip dont-vary
#SetEnvIfNoCase Request_URI \.rm$ no-gzip dont-vary

##Approach 2: Explicit ("Add") compression by mime-type

AddOutputFilterByType DEFLATE application/x-httpd-php
AddOutputFilterByType DEFLATE application/x-httpd-fastphp
AddOutputFilterByType DEFLATE application/x-httpd-eruby
AddOutputFilterByType DEFLATE text/html
# Or by extension
# AddOutputFilter DEFLATE html
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE image/svg+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/atom_xml
AddOutputFilterByType DEFLATE application/x-javascript

# Implicit compression on the way in
SetInputFilter DEFLATE

# Explicit compression on the way in, there is no AddInputFilterByType
# AddInputFilter DEFLATE html

IfModule>

<IfModule mod_deflate.c>
SetOutputFilter DEFLATE
SetInputFilter DEFLATE
#the two above compress everything unless excluded below
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary              
SetEnvIfNoCase Request_URI \.avi$ no-gzip dont-vary             
SetEnvIfNoCase Request_URI \.mov$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.mp3$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.mp4$ no-gzip dont-vary     
SetEnvIfNoCase Request_URI \.rm$ no-gzip dont-vary      
SetEnvIfNoCase Request_URI \.plist$ no-gzip dont-vary   
# Below is an example where you get rid of what's above and you explicity compress
AddOutputFilterByType DEFLATE application/x-httpd-php application/x-httpd-fastphp application/x-httpd-eruby text/html 
DeflateFilterNote ratio
DeflateCompressionLevel 9
IfModule>