"PHP provides an alternative compression method (two actually) and this is exactly what we'll leverage here - so one could think of this method as a 'poor man's mod_gzip'."

"Open up your style.css.php, or whatever you named it, file and add the following snippet of PHP to the very top: <?php if(extension_loaded('zlib')){ob_start('ob_gzhandler');} header("Content-type: text/css"); ?>

Then, add the next line to the very bottom and save the file: <?php if(extension_loaded('zlib')){ob_end_flush();}?>"

I went with the second guide; "I will now explain how to implement Comet with PHP programming language. I will demonstrate it on two demos which uses two techniques: the first one is based on hidden ”<iframe>” and the second one is based on classic AJAX non-returning request."

"We don't actually loop infinitely server side. You may have noticed the logic for the while loop - if we've executed for more than 30 seconds we discontinue the loop and return nothing. This nearly eliminates the possibility of substantial memory leaks. Also, if we didn't put a cap on execution time we would need to print a "space" character and flush output buffers every iteration of the loop to keep PHP abreast to the status of this process/connection. Without output being sent PHP cannot determine if the connection was lost via connection_status() or connection_aborted(). As a result this could lead to a situation where there are an increasing number of "ghost" processes eating up server resources. Not good!"

"You probably don't want to use flush in any other place than right after the header. A browser usually won't render unclosed html tags, so delivering a partial page won't display things any quicker."

This was useful for implement "email.php", as described in the Evolt article.

"The most important difference between the two is that a string enclosed in double quotes is parsed by PHP. This means that any variable in it will be expanded."

For hosts with cPanel.

Using EXIM as a MTA.