[crest]

Unspeakable horrors like changing `$[` in old Perl5 versions to mess with someone's mind? Who doesn't like array indices starting at 0, 1, ... or 42?

[jonocarroll]

In Dyalog APL you can set the index origin with ⎕IO←0 (or 1) and there are many ways in which this can bite you. In Lua, and I think Fortran, you can specify the range of array indices manually.