Can I use Apache 2.2.15 with mod_rewrite enabled? I currently am running Centos 6 which only comes with Apache 2.2.15.  Yeah, I know it is about time for me to upgrade...  I get the following warning:


  The minimum version of Apache needed to run Drupal without mod_rewrite
  enabled is 2.2.16. See the enabling clean URLs page for more
  information on mod_rewrite.


I have mod_rewrite enabled. Am I okay as is? I don't care about pretty URLs at the moment as I am just learning about Drupal, and will upgrade my OS someday soon.
Yes, you can go with Apache 2.2.15 as long as you have mod_rewrite enabled (so you'll have pretty urls).

From Drupal issue Regression fix: allow Drupal 8 to work without Apache mod_rewrite


  Apache 2.2.16 is only required if mod_rewrite is NOT enabled