There are plenty of brewing tools out there, but ito data model and workflow they are all basically descendants of ProMash. I wanted something that approached home brewing with a focus on process instead of ingredients.
My data model of a "recipe" is a DAG of typed process steps each of which can have ingredients attached. Liquid volumes move through the DAG and are modified at each step. Outputs of the recipe are at the leaf nodes. This model can represent any wacky brew day you can dream up - including and not limited to multiple mashes, splitting or combining volumes pre or post mash/sparge/boil/cool/ferment/whenever, packaging wort, etc. The regular tools usually can't even represent a partigyle batch properly.
Honestly for my regular 20L single-infusion no-sparge brew day it is probably slightly less convenient than say Beersmith. But for unusual situations it shines. For eg this past festive season I found myself needing to stock up quickly. Designing a 40L "one mash, one boil, two different beers [1]" double batch brew day was easy, and hitting all the numbers along the way for such a mad-hatter exercise was incredibly cool.
[1] Scottish Export and Sweet Stout