I made a batch of Tomato Jam this summer. Lots of different recipes but the one I used didn't use >
added pectin. (There's plenty in the tomato skins) It was chunkier and sweeter than ketchup but really, I thought it was fairly ketchup-esque.
Mind you, I really like ketchup but there was quite a bit of work involved in processing the jam, 2 hours cooking it down, canning, waterbathing etc., etc. I think there might be something there but next time we have a surplus of tomatoes, I'll be trying a variation with hot peppers . . . for that little extree punch.