Today, Ev Williams' latest startup, Medium, added some tools to bring people together while they're writing. The collaboration tools are similar to what you'd find in Google Docs, but the key is to work on something to share publicly, together. The service isn't open to the public yet, but it's a beautiful set of tools to help you write about the things that interest you and then file them away in collaborative groups and categories called "Collections." You can add your own posts to someone else's collection, creating a fun, and social environment for writers. In a post called "Don't Write Alone," Williams discusses the new features and the philosophy behind what Medium is building as a whole: Since starting Medium, we’ve maintained a focus on collaboration. We’ve touched on it with collections, which allow many people to contribute to the same idea. But today we’re taking it a big step forward with pre-publish collaboration. Within your post, you're now able to click an "invite collaborator" button on the top-right of the page once you've saved a draft, which gives you a link to send to friends: Once you've done that, the person can then come in and add notes to certain sections on your post: After the post is published, the people who worked on it with you get their due credit automatically: Even posts that are public can be annotated, with the author having the choice of whether to make your additions public or not: In a way, this is a re-imagination of commenting systems, where instead of a slew of comments showing up below a post, points can be made about particular passages, opening up a new avenue of discussion. It's interesting to watch Medium evolve, as we know that Williams has come from creating Blogger to shoving Twitter into the mainstream. It looks like all of the little things that Blogger never had as a publishing platform are now being put into the Medium product. The interesting use case for something like this is when your friends take a look at your posts and catch some typos, or perhaps a link that doesn't work. Instead of firing off an email to you or an instant message, you can see notes in-line and then take action on them before or after you've published. You really get a sense for how useful this is once you see notes dropped into your own posts: Imagine being able to write an article together and then publish it, which is something that you can't do on any other competing service. I wouldn't mind trying it out. Nor would I mind being able to launch a note into a new post, giving that person the credit for sparking a new idea for me. Williams says that Medium's mantra is that "People create better things together." That's certainly a different approach than the solo nature of tweeting and blogging as we know it.