A great IDE to learn array languages for most people: Excel/Google Spreadsheets.
No, I am not kidding. Excel, or spreadsheets in general, is a great, readily available environment to learn how to think like an APL programmer. Sure, the notations are not there, and you will be copy-and-pasting cell references as opposed to typing in obscure operators, but the essential idea is there: how to think about computation in a geometrical/tabular way.