Looking for a avs editor (I don't remember the name)

Hi, I'm searching for a editor for avs scripts, but I don't remember the name. It was just a text editor which let to preview the ending video in the editor itself and let to create sliders to change the values of the filters (it needed to add some code in the script to use this) Anyone has a idea of wich editor I'm talking?

That must be the great AvsP, have a look here:

It is. Thanks a lot.