Currently available to read - and rate and comment on - are short IFs from a handful of authors including myself. Most notable amongst them is Emily Short, legendary author and critic of interactive fiction, who created my all time favourite game, Galatea.
Varytale is developed by Failbetter Games, who you might know from Fallen London (once called Echo Bazaar) or their less famous tie-in to Erin Morgenstern's The Night Circus (which, by the way, I highly recommend).
While I'm on the subject, Failbetter recently announced a new system, StoryNexus, which builds off of the work they did with Fallen London and the impression is it will follow a similar structure. Failbetter's head, Alexis Kennedy, described the differences between the two systems thusly:
"StoryNexus is more game-y; Varytale is more book-y. StoryNexus is easier to use; Varytale is more customisable. We're concentrating on StoryNexus for now."So that's a fistful of new interactive fiction experiments to read, and two systems to play with. Good news, I say.