Excel is a brilliant tool for solving problems that can be expressed as arrays. But its not that nice for trees. A first step to this project could be to make a

Excel is a brilliant tool for solving problems that can be expressed as arrays. But its not that nice for trees. A first step to this project could be to make a satisfying experience for editing this kind of data. Here's an example: you have a list of categories and products. In excel today, you'll probably put category in column A and product in column B. But now you have lots of duplication of category ids. You can't change the category in one place like you'd be able to it was explicitly a tree, and rearranging branches of the tree is tedious. Creating arbitrarily deep sub-categories is a mess. If someone could make a good experience for this problem, then it might inspire ideas for the more complicated task of programming.