Bonus Socius
Source?, 1300
#2
4 + 5
5658 | Beispiele zur Ideengeschichte des Schachproblems (Josef Breuer) | 1982 |
3310 | 2345 Chess Problems | 1997 |
5454 | Near Snap | 2021 |
This anticipates 231593(1927)
There are these versions: 77321
Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) &
CSS/Javascript (jQuery, Bootstrap & DataTables).