Error messages go in the *log*, not the *output*

A fairly fundamental rule of software, here: if you have a non-fatal error, you write it to the log. You don't present it to the end-user, particularly if you're providing a service. What do I care that you can't create a thread, particularly if you went on to render the whole page anyway?

According to Netcraft, sluggy.com runs Apache 1.3.31 on FreeBSD. Worth reading!