Lemon curd is basically egg yolks thickened with sugar, butter, and lemon juice. As it cools, it turns a beautiful, bright yellow color, and can taste anywhere from slightly tart to full-out tangy, depending on how much lemon juice you use. [I, personally, like mine on the tangy side, because in layer cakes, the frosting is sweet enough to combat the zing from the curd].
I made this share of lemon curd for a layer cake, the recipe for which I'll post up separately.
It's in the fridge right now.
Can't promise it'll still be there tomorrow.