This option specifies whether resources (script and CSS files) are compressed by the server before being posted to the client. The resources are compressed by a factor of 4 or 5 to about 20% of the file's original size.
<configuration> ... <devExpress> <compression ... enableResourceCompression="true" ... /> ... </devExpress> ... </configuration>
You should register the DevExpress Web.config section to apply these settings to your project.
This option is enabled by default.