Is this the eternal question ? I think community is 50% divided.

In some servers it works better Off, and in anothers On.
And i'm not talking about image or file servers... just all the same, virtual hosting of typical home pages...

It entirely depends on the type of traffic being served but in 90% of cases if you are doing more than 10 req a sec then keepalive off is required

It depends on the server, the only reason I stated keepalive should be off is for special circumstances.

A server that does strictly images/files keepalive is best off.

I like to keepalive off during a DOS attack while tweaking some of the other settings as it generally helps keep the server online for longer.

For your general run of the mill virtualhosting server keepalive is best left on.

I disagree. If a site is serving 500 clients and each apache process is 8Mb (500*8=4000mb) of real ram.

As I have posted in the other threads it depends on the server. In my experience I like to leave keepalive on but tweak some other server values. It is easy enough to test it both ways to see what works best for the OP.