Amiga E was one of the first programming languages I tried to learn. I had started with Apple BASIC, and happened to get a free Amiga E compiler and booklet on some Amiga magazine. The booklet left a lot to be desired; specifically, it showed how to do output but not input, and as a clueless novice BASIC programmer, I naively assumed that Amiga E could not do input.
I did not write much of interest using Amiga E, and that booklet was nowhere near as useful as K&R.
I started with probably the same booklet from probably the same magazine, but I also found a more complete reference making the rounds on local bulletin boards, so I was able to figure out input, and finally ordered the full language package from the author. Wouter van Oortmerssen is still working on nerdy pursuits, and created some other languages over the years, but none were as popular/successful as Amiga E. I made a small sample playback app with it, but my ambitions were far beyond my abilities.
I think it's primary reason for popularity was that it was so easy to use the Amiga GUI elements and other special features of the Amiga OS and hardware. I always had a hard time making stuff work in C, but could build a UI in no time in E.
I did not write much of interest using Amiga E, and that booklet was nowhere near as useful as K&R.