How to find Apache Version in Oracle Apps 11i

Login to Web tier as applmgr user
cd $IAS_ORACLE_HOME/Apache/Apache/bin
Run the following command
./httpd -version
You will see the output like below

Server version: Oracle HTTP Server Powered by Apache/1.3.19 (Unix)
Server built: Dec 6 2005 14:59:13 (iAS 1.0.2.2.2 rollup 5)
Which means you are on iAS Version 1.0.2.2.2 with patchset rollup 5 with Apache Version 1.3.19