RENXT is the new-ish cloud version of Raiser's Edge (which as I wrote before, still looks suspiciously like Raisers Edge 7). There is a SKY API where you can poke about with the data but if you want to download the whole lot regularly and have a local copy, there is a way to do that too.
Quite a lot of the charities I've worked with have used Blackbaud's The Raiser's Edge for fundraising. Version 7 was launched in July 2000 and was a client-server Windows database app. At the time it was very compelling, with lots of features tailored to charity fundraising. I remember being impressed by the Query Editor that was built in: