Our script policies allow you to add interactive features to your Web site. That means you can add blogs, forums, feedback forms, and just about anything else you can imagine.
The only thing we don't allow are "background processes", which means software programs that act as servers or that aren't really related to running your Web site and e-mail service. In particular, the following are prohibited:
In addition, programs should generally run for only the time necessary to handle incoming requests, then exit (FastCGI scripts are okay because even though they may keep running for few minutes, they soon exit if there are no more incoming requests).
Even if a background process isn't CPU-intensive, such processes use memory and other resources that are needed for other scripts. We're occasionally asked if it's okay to use background processes that sit idle for a long period of time and therefore have their memory "swapped out to disk", on the theory that these processes don't use much real memory. Unfortunately, that's not okay, either: when these kinds of programs are eventually accessed, they cause the server to access the disk to reload the memory, which can bring an entire server to a halt for several seconds. We take great pains to avoid situations that can cause our servers to have to "swap" memory.
For more details about our script policies, please see the topic "Script Policies".