This is also how the TeX program works. Of course it has lots of variables (hundreds of "global" variables in fact), but for everything whose size may vary (boxes, lists of characters, lists of tokens for macros, …), it has two giant arrays of fixed size, one called “str” (aka the string pool, used for strings), and one called “mem” (used for everything else). It's this way partly because of the limitations of Pascal at the time.