This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
=shift; { print; my (%cnt, %saw); $cnt{$'s wiki page.
=shift; { print; my (%cnt, %saw); $cnt{$ has authored 0 sequences.