What they said:Northern Ireland Secretary of State Peter Hain: "It's going to stick, I believe, because the DUP and Sinn Féin are the two most polarised forces in Northern Ireland's politics, they have done the deal and that's why I believe it's here to stay for good."
UUP leader Sir Reg Empey: "The mission of the UUP in the months and years ahead is to demonstrate that unionism and politics in general is not about a sectarian power-grab."
SDLP leader Mark Durkan: "What today shows is that when finally you have a government setting a deadline and setting terms and keeping to them, you can get somewhere. In the past, we had Sinn Féin being underwritten and they came up short on decommissioning continually. We had the unionist leadership being underwritten and coming up short on the powersharing institutions. It took people like the McCartney sisters to show governments how to set terms and hold terms in which the IRA had to move."
Sinn Féin president Gerry Adams: "Today is another significant landmark in the process of transforming life on this island. I genuinely believe that we are all shaping a real process of national reconciliation and building a new relationship between the people on this island and between Ireland and Britain."
Former British prime minister Sir John Major: "The sight of people that were once totally antagonistic to one another sitting down to plan the future of Northern Ireland is very attractive. I always believed that it was possible but that it would be difficult and that it would take a long time. All of those things turned out to be right."
Alliance leader David Ford: "We have heard all the hype, now it's time for Sinn Féin and the DUP to get on with the serious business of delivering better services for everyone and improving our local economy."