My favourite Montreal summer festival. Have been attending for years! I have been a fan since it was on St-Denis. There's always entertainment; street performers, large venues, random characters and now more recently being at the Quartier de Spectacles, there are food trucks. Definitely recommend in checking out the line-ups each year as there's always a fan favourite comedian in town... you will most definitely get a chance to meet and take pictures with them! Or enjoy the free shows/concerts!
Have fun!