It seems like there were no source files for most of Dyalog APL's history. Instead, images held code and variables. You would pass them around to work with other people. While there are features such as LINK nowadays that make this irrelevant, one can stumble upon forum posts on how to share or run code with images in bewilderment.
我很乐意把伊藤信吾（Johnny）看作是给京都 “醒脑” 的人。
。关于这个话题，新收录的资料提供了深入分析
Emacs configuration with one strict rule: no external packages.
reimplementation of the popular ace-window package.