How about a single standalone function named as debug from https://github.com/hazardland/debug.php.
Typical debug() html output looks like this:
But you can output data as a plain text with same function also (with 4 space indented tabs) like this (and even log it in file if needed):
string : "Test string"
boolean : true
integer : 17
float : 9.99
array (array)
bob : "alice"
1 : 5
2 : 1.4
object (test2)
another (test3)
string1 : "3d level"
string2 : "123"
complicated (test4)
enough : "Level 4"
