[chancho]

Just to pile on: 0-based indexing is also more convenient when you want to build a multi-dimensional array from a one-dimensional array primitive using the integer division and modulo operators to map between 1D and nD indices. E.g., a matrix with M rows and N columns can be mapped to the range 0 <= i < (NxM) by letting i = (row * N) + col, and the backward mapping is row = i / N, col = i % N.

If instead you use 1 <= i <= (NxM), 1 <= row <= M, 1 <= col <= N, then the mappings aren't nearly as clean. Sure, you could hide all this behind some kind of API, eg. Image.getPixel(x,y), but if you work with multidimensional arrays very often, eventually you'll need to marshal arrays back and forth between different containers that use different access APIs, and the simplest common representation to use for this kind of data is as a 1D array, so being able to work with nD data that is stored in a 1D array comes up fairly often.