I think that the biggest concern will be the library-modules (PERL5LIB equivalent). I know that Windows implementations use registry-keys for this ... I presume that both Strawberry and AS do this and with their own distinct keys. I expect that perl -V, with a capital V, will print out the library search-path as before. What you really want to make sure of is that one Perl implementation doesn’t reference the Perl packages (including underlying XS bits ...) that were built and used by the other. The module installation and configuration process often does a lot of low-level compiling, and I expect that it will be quite specific to this, vs. that, Perl implementation on the same box.