Mentioned on my blog, but other people here may also be interested:
Archive of Our Own runs a Yuletide project in which participants write each other stories in different fandoms, as a holiday gift. This year’s Yuletide haul includes several IF pieces:
Bigger Than You Think, an astonishing xkcd/Italo Calvino fandom crossover about exploring untold caves. Glulx, but it plays with a hyperlinked keyword interface for greater friendliness.
And a Hippo New Year, a parser-based I7 game hosted on Playfic, in which you play a mouse-sized hippo.
Out of the Night, which deals with the experiences of Dale Cooper after the end of Twin Peaks. Ren’Py, with extensive imagery.
The names of the authors are concealed until Jan 1, but there’s some sweet stuff here. Check it out.