Unfortunately, no one can be told what Matrix is. You will have to see it for yourself.
$ go install github.com/jsageryd/matrix@latest
$ matrix -h
Matrix
Flags:
-c string
colour (default "white")
-f string
feed (default "alpha")
| Valid colours:
| white, blue, green, red, yellow, orange, magenta, cyan
|
| Colour can also be changed by typing the initial
| (e.g. 'c' for 'cyan') while running.
| Valid feeds: alpha, binary, block, cyril, dot, greek, hangeul, jamo, hex, hira, kata, line, num, stdin, zh
|
| Feed can also be changed by typing the upper-case initial
| (e.g. 'A' for 'alpha') while running.
| Hex feed uses X. Binary feed uses 0.