Computer Environmental Controls

I'm sure there are operations out there in which the environmental controls of the room are controlled soley by a computer system. By computer system I mean a Pentium of some sorts w/ monitor, kb, mouse, and some software. All of this connected to a thermometer/heater/cooling fans, lighting, watering, humidifying etc.

Has anyone else thought of this setup? And does anyone know what kind of software is out there that can help in connecting of these monitoring systems and automated lighting and watering schedules to a computer box?

i know of some shit that i used in chemistry and physics in previous years in high school that hook up to computers that measure temp and things like that, all you'd need is the right equipment and a program that works with that equipment, research it on google or something