Feather

According to information revealed by time travelers, the esoteric language Feather exists in some hypothetical futures, and will be made by User:ais523. However in other futures the mere idea has caused him to go completely insane before he could make it, while in others again he has kept some of his sanity by indefinitely abandoning the concept. It still remains to be seen which future will be realized in our own timeline, although so far evidence sadly seems to point to the third option.

Crude shadows of the protoideas of Feather may be picked up by people willing to risk browsing logs of the #esoteric IRC channel. The most relevant log is probably this one (start around 08:41), in which ais523 explains pretty much the entire known state of Feather development. It's important to note that most (all?) details of the language have not been pinned down; the attempt is more to find anything that works, rather than to implement a specific specification.

Here's an excerpt where ais523 explains the origins and basic idea of Feather (believe it or not, it's inspired by Smalltalk): Feather subsequently became something of an inside joke in #esoteric, due to ais523 refusing to talk about the details, and yet still insisting that the language was real, just he couldn't make it work and refused to think about it in order to avoid going mad (and recommends other people do the same).