What Software Would Be Best For This? (iMac Computer Lab)

Hello, my question is what would be the best method for the following:

We have a computer lab with 36 mid 2010 27" iMacs all running off one wifi network. They are also hooked to our 6TB 5Big NAS through the Airport Extreme.

We have Lanschool installed, and that works great when we are teaching a class.

However my question is, what would be the best // easiest // free-est way to be able to do something like install an application on all of them at once? Instead of manually going to each one and installing something, or deleting an app.

Thanks.