Shortly after iconic CBS late-night host David Letterman announced his plan to retire in 2015, Twitter reaction began to pour in from a wide-range of celebrities — and even President Obama — reflecting on the comedian’s legacy. See a selection of those tweets below (more to come):

Arsenio Hall also sent a longer statement to EW: “David Letterman is a legend. I have had the unique pleasure of watching him as a fan and competing against him as a fellow host. He has set a standard for comedy in late night that I strive to achieve every single day. When I decided to come back to late night and compete against Dave, I received a phone call asking me to be a guest on Dave’s CBS show for the first time. Dave put me on his show 72 hours before I debuted. Dave showed that the only thing that matches his comic genius is his class. Late night might fill his time slot but it can never fill the void he will leave behind. He is simply the best.”