I am used to using Cubase on Windows Vista. Is there anything on Ardour like the VST instruments on Cubase? thanks

The closest thing to VSTi’s would be the LV2 instruments (mono synth and organ) in the Calf plugin, but as seablade said, these are run outside of Ardour and connects to it through Jack

There is no MIDI support(And thus no instruments) in Ardour 2. There is in Ardour 3, but that is currently under development and not ready for testing at this time really. What many people do is run a seperate MIDI program’s audio outputs into Ardour via Jack,a nd use that to run virtual instruments.