# Wild card

*[Repost of 2020](https://codegolf.meta.stackexchange.com/a/20615/97857).*

For a deserving challenge, answer, or user that isn't a good fit for any of the other categories.

## [quintopia](https://codegolf.stackexchange.com/users/47050/quintopia)'s [Befunge-93 in Befunge-93](https://codegolf.stackexchange.com/a/219764/80214)

Interpreting Befunge 93  is already not very easy, but doing it within Befunge 93 is a behemoth in itself. This uses the existing features of befunge to simulate the program within its own playing field!

## [Jo King](https://codegolf.stackexchange.com/users/76162/jo-king)'s [quantum quine](https://codegolf.stackexchange.com/a/232976/100664)
**Nominated by emanresu A**

When I wrote this question, I didn't believe it was possible to create a program with a score of 0. It's hard to make a program that *functions* when any character is removed, and even harder to make a *quine* that *stays a quine* when any character is removed, let alone one that behaves in such a specific way.

Jo King's answer uses [Backhand](https://github.com/GrayJoKing/Backhand), a language which skips every few characters to make [tag:restricted-source] a bit easier, and even then it's still a quite complex answer.

## [m90](https://codegolf.stackexchange.com/users/104752/m90)'s [answer](https://codegolf.stackexchange.com/a/231006/92901) to [Final tribute to John Conway: FRACTRAN self-interpreter](https://codegolf.stackexchange.com/q/204779/92901)

**Nominated by Dingus**

The previous best solution known for this problem, at 48 fractions, had stood since 2017. It was blown out of the water by @m90's 30-fraction solution, which was accompanied by an excellent explanation.

## [tjjfvi](https://codegolf.stackexchange.com/users/87606/tjjfvi)'s [answer](https://codegolf.stackexchange.com/a/233759/92901) to [Complement a POSIX Extended Regular Expression](https://codegolf.stackexchange.com/q/24352/92901)

**Nominated by Dingus**

This challenge had gone without an answer for over 7 years, and a quick survey of the comments reveals just how difficult it was perceived to be: 'It's possible, but crazy tedious ... slightly harder than writing a complete RE engine!', 'Supporting escaped meta-characters is honestly going to be a challenge in itself', 'The code I have so far is basically 30KB'. And indeed, @tjjfvi's well-explained code is a complex beast, transforming regex → tree → DFA → regex, all in less than 1.6 kB! This answer could easily have been nominated for Most Complex Answer or Best Explanation, but @tjjfvi already has another worthy contender in those categories!