It doesnt have to be on PHP. I will take the option that better meets my needs. And no, the forum is not mine so it has to be something that works externally. Is PHP the best option then? Because please keep in mind that it the script, program, bot or whatever is called should work automatically without operator.
I only need to post on one forum. The bot should check every minute or so whether there is a new comment from a certain user and reply immediately. I guess that if this is done on PHP I would require to set a cronjob for my server to run the script automatically, right?