Yes, the "electric" GUI was incredibly fast and effective. The K2 GUI was basically the only GUI system I've ever used in which it is easier to write a GUI for a simple system than a batch command line. It looks basic and wouldn't have won any design awards, but it was crazy fast and crazy effective. See e.g. The S- spreadsheet (copied here in its entirety), see near the bottom of
http://nsl.com/papers/spreadsheet.htm for screenshots and discussions
S..t:".[`D;(;);{. y};S[]];S[.;`f]:9$D[]"
S:D:.+(`a`b`c`d;4 6#,"")
Other examples:
http://nsl.com/papers/puzzle15.htm ,
http://nsl.com/papers/calculator.htmI suspect the reasons it was removed were:
(a) it was a lot to maintain compared to the rest of the k environment, as it needed to be implemented for all systems independently (X, Win, Mac at the time), and introduced dependencies that were about 10x larger than the base system.
(b) it wasn't actually a selling point - being simple and local GUI meant that while it was nice for the programmer users, it wasn't useful for end users, who usually had no K license of their own, and who expected everything to be web-able and importable to Excel.
(c) it wasn't extendable with more widgets. Needed a small HTML control or video player in your GUI? touch luck.
