> Books are great (unless you're Socrates). We now have magic ink. As an artifact for effecting the transmission of knowledge (rather than a source of entertainment), how can the book be improved? How can we help authors understand how well their work is doing in practice? (Which parts are readers confused by or stumbling over or skipping?) How can we follow shared annotations by the people we admire? Being limited in our years on the earth, how can we incentivize brevity? Is there any way to facilitate user-suggested improvements?
The great thing about books is that no matter how long they've been sitting around, it's easy to take one off the shelf and read it. The cultural infrastructure of written language has been around much longer (and been much more stable) than the computational infrastructure you'd need have your "magic ink" still work in 1000 years. At some point we need to start treating computers and software more seriously if we want to have things like this.