HLL's (at least those which have a VM) often try interesting techniques to combat this, since string handling is so often a performance problem (it's a performance problem because they often make it relatively painless to manipulate strings, at least to the point where it's not obvious you may be doing something really inefficient). It's interesting if you follow the development of a language while it's being developed, you can usually see a few of the techniques they've used come and go. Starting with simple string handling, then global shared copy-on-write strings, then ropes, possibly a fourth weird representation, and likely back to one of the prior, simpler models.

At least, that's what I hazily recall from the long, jumbled Perl 6 history, but that includes a few changes to the language and multiple VM's and multiple string handling regimes per VM, sometimes.