[Andrew MacIntyre]
OS/2 EMX (2.2.1 without pymalloc) justpush 0.59 justzip 8.85
OS/2 EMX (recent CVS with pymalloc) justpush 0.54 justzip 8.81
FreeBSD 4.4 (2.1.1 w/o pymalloc) justpush 89.72 justzip 110.41
FreeBSD 4.4 (recent CVS with pymalloc) justpush 19.21 justzip 46.32
The FreeBSD box is more mature hardware (P5-166).
By "more mature" in this context I assume you mean more "obsolete" than "better developed".
I'm surprised at the difference in the 2 sets of results on it. AFAIK, the compiler version and switches are identical for the two interpreters (the 2.1.1 is from the binary package on the FreeBSD 4.4 CDs).
justpush() primarily tests realloc() speed, and pymalloc isn't (yet) involved in managing list-gut memory. So I expect this has much more to do with the libc(s) they're using than with the compiler(s).