I'm impressed Trello has managed to succeed in what many had written off as overcrowded space. I think the key to its success is the insight that Joel Spolsky e

I'm impressed Trello has managed to succeed in what many had written off as overcrowded space. I think the key to its success is the insight that Joel Spolsky explains in his post here: http://www.joelonsoftware.com/items/2012/01/06.html http://www.joelonsoftware.com/items/2012/01/06.html - that successful apps often provide a new kind of data structure, that makes them suitable for many purposes. (For Trello, that's a "list of lists".) I don't think the data structure was the innovation for Trello. There were lots of products out there that had the columns-of-cards structure. Was (and is) a feature of many agile project management products - following the cards-on-the-wall structure used offline by agile folk. What Trello did - which was brilliant - was sell that as a solution to everybody. Not just the project management folk in dev companies, not just for dev folk, but for folk planning/organising anything. It's spotting that that data structure is generic.