ftp://ftp.unc.edu/pub/empd/products/EDSS/test/public_domain/plplot_old/sys/  direct

[DIR]vms/  direct  4489+ twin directories
[DIR]unix/  direct  22787+ twin directories
[DIR]os2/  direct  7150+ twin directories
[DIR]dos/  direct  3762+ twin directories
[DIR]amiga/  direct  12946+ twin directories