Keep ALL the versions

Back in the 1980s, storage was expensive and slow. You had a copy of your document in memory and you would be asked every time you wanted to save it out to disk, because you didn't want to fill the disk up. That paradigm is so out of date now it's embarrassing to try to explain to my sons what the little floppy disk icon is in Microsoft Word. "What's that?" "it's a floppy disk." "Oh yeah, I think I saw one in the garage once"

The world view of having to load and save is being gradually eroded. Apple has changed the operating system - Mountain Lion no longer has Save and Save As, but instead a model of going back through edit histories. Google Docs originally didn’t have a floppy disk icon, but put it back because people were looking for it in user testing. Now it has been removed.

We've had source code control as programmers for a long time. But the github world takes that further: the first thing you do is clone a project into your own repository, then start forking it. You can eventually merge stuff back later, but there is the assumption that things are happening in parallel. As James Governor put it:

Open Source used to count download numbers as a measure of developer success.

Today, we increasingly use forks as the metric of traction.

Wikipedia has put this into the public consciousness by having publicly visible edit histories, so you can go back and forwards in time over the history of the article. The paradigm of "storage is not a problem, we should keep every version of everything ever" is moving through culture to be a default assumption.

This will be something we want on mobile too. The issue of "which have I got on the phone and which have I got in the cloud?” is what makes it tricky. I think there will be a battle between Apple and Google about how you present that to the user in a coherent way - Google Drive and iCloud are taking different paths here, with DropBox actually working between both. Google Drive not storing copies of Google Documents locally is a mistake I expect them to fix.

Everything is moving in this direction, even low level system design. The growth of functional programming is all about not having contention over a single copy of things in memory but having paths through data that are modifying things in their own version of the world.

If you think about the difference between the way JavaScript handles stuff and the way Java does, Java still has a ‘data structure being passed around’ world view; JavaScript has closures that are passed around that contain the entire state of the current machine at the time of that event which are held as you go off and do something else and come back. One of the reasons that node.js feels so nice when you're writing web programming is that it has the feeling you’re used to on the client side that you do something and then call something, passing it a callback. You end up writing the server side stuff in the same way, and it's just naturally parallelizable. It's easy to spin up more machines for it because you've written stuff with the presumption that each instance of it is wholly independent.

Not everything can be written that way. The core of node is in C because it has to deal with the raw machine contention and deal with this routing, but the spread of the functional world view is a natural fit for web apps.

The other potential that node.js makes manifest is convergence of client and server code. If you're running and writing the same code in the same language, with the same libraries running on both the client and the server you can decide to migrate bits back and forth much more easily.

You don’t have to spend so much time deciding which is which and without worrying about the boundaries of the world and different shapes of the data structures. So if you're creating a JSON object on the server and passing it to the client you can decide whether you do that or not, at which point you do that, at which point you render it and which point you don't. That sort of fluidity is going to become more important over time. Pat Patterson showed how this can work for mobile apps too.

The programmers' world view has changed on this and it is permeates out to the world as programmers make those ideas available to the public in usable form. The invention of ‘Undo’ was a huge part of what made the Mac great - enabling users to experiment safely. Being able to retrospectively undo mistakes later, or learn from others’ public variations on a theme is going mainstream too.

This post is based on discussions I had on This Week In Google ep 143, with Gina Trapani, Jeff Jarvis and Tom Merritt which were transcribed by Michael Shook from this video of the show Updated: At the same time, JP Rangaswami wrote Warning: Contains Warnings which give more context about how 'Undo' helps protect innovation.