testing on recent POSIX systems (ie Test::Harness > 2.99):
  perl Makefile.PL -xs ; make distclean ; perl Makefile.PL -xs ;
    make && make test >xs.test.out 2>&1
  perl Makefile.PL -pp ; make distclean ; perl Makefile.PL -pp ;
    make && make test >pp.test.out 2>&1
  echo === XS make test output ===
  cat xs.test.out
  echo === PP make test output ===
  cat pp.test.out
  echo XS: `grep Result xs.test.out`
  echo PP: `grep Result pp.test.out`
  rm -f xs.test.out pp.test.out
# otherwise, use this:
  perl Makefile.PL -xs;make distclean;perl Makefile.PL -xs &&make &&make test
  perl Makefile.PL -xs;make distclean;perl Makefile.PL -pp &&make &&make test

## last tested version list, ? = not yet tested
osname/os-friendly-name+distro,etc/kernel-version/arch/perlvers/ccname+version
if (XS|PP) is specified, it means that method passed but the other failed.
otherwise both were tested. a version of FAIL means no version has passed.
CC KEY: gcc = gnu cc, sc = Sun C
-----------------------------------------------------------------------------
darwin/OSX 10.5.5/9.5.0/i386/5.8.8/gcc-4.0.1:                0.99_02PRE-r611
darwin/OSX 10.4.11/8.11.0/ppc/5.8.6/gcc-3.3:                 1.00
dragonflybsd/2.2.0/RELEASE/5.10.0/gcc-4.1.2:                 0.99_01
freebsd/4.11/GENERIC/i386/5.5.3/gcc-2.95.2:                  0.99_02PRE-r611
freebsd/6.2/GENERIC/i386/5.8.8/gcc-3.4.6:                    0.99_02PRE-r611
HP-UX/11i v2/B.11.23/PA-RISC/5.8.2/HP C-ansi C:(2)           1.00
linux/debian lenny/2.6.29-rc3/arm-gnu-eabi/5.10.0/gcc-4.3.2: 1.00
linux/debian lenny/2.6.26/i686/5.10.0/gcc-4.3.2:             0.99_01
linux/debian lenny/2.6.26/sparc64/5.10.0/gcc-4.3.2:          1.00
linux/debian etch/2.6.18/alpha/5.8.8/gcc-4.1.2:              0.99_01
linux/debian etch/2.6.18/hppa/5.8.8/gcc-4.1.2:               0.99_01PRE-r544
linux/debian etch/2.6.18/ia64/5.8.8/gcc-4.1.2:               0.99_01
linux/debian etch/2.6.18/ia64/5.8.8/(3):                     0.99_01
linux/debian etch/2.6.18/i686/5.8.8/gcc-4.1.2:               0.99_02PRE-r611
linux/debian etch/2.6.18/x86_64/5.8.8/gcc-4.1.2:             0.99_01
linux/debian etch/2.6.18/ppc/5.8.8/gcc-4.1.2:                0.99_02PRE-r611
linux/ubuntu intrepid/2.6.27/i686/5.10.0/gcc-4.3.2:          1.00
linux/ubuntu intrepid/2.6.27/x86_64/5.10.0/gcc-4.3.2:        0.99_02PRE-r611
linux/ubuntu hardy/2.6.24/x86_64/5.8.8/gcc-4.2.3:            0.99_02PRE-r611
MSWin32/?/?/?/?/MSVC: (XS)(4)                                0.99
MSWin32/XP home SP3/strawberry/x86/5.8.8.4/gcc-3.4.5: (XS)   0.99_02PRE-r611
MSWin32/XP home SP3/strawberry/x86/5.10.0.4/gcc-3.4.5: (XS)  0.99_02PRE-r611
MSWin32/XP home SP3/CYGWIN_NT-5.1/x86/5.8.8/gcc-3.4.4:       0.99_02PRE-r611
netbsd/4.0/GENERIC/i386/5.8.8/gcc-4.1.2:                     0.99_02PRE-r611
openbsd/4.3/GENERIC/i386/5.8.8/gcc-3.3.5-propolice:          0.99_02PRE-r611
Solaris/5.10/2008-10/sun4u/5.8.4/sc:                         1.00
Solaris/5.10/2008-10/sun4u/5.8.4/(1):                        1.00
Solaris/5.10/2006-06/i86pc/5.8.4/(1):                        0.99_02PRE-r611
Solaris/OpenSolaris2008-05/snv_86/i86pc/5.8.4/sc:            0.99_02PRE-r611
Solaris/OpenSolaris2008-05/snv_86/i86pc/5.8.4/(1):           0.99_02PRE-r611
Solaris/OpenSolaris2008-11/snv_101b/i86pc/5.8.4/sc:          0.99_02PRE-r611
Solaris/OpenSolaris2008-11/snv_101b/i86pc/5.8.4/(1):         0.99_02PRE-r611
Solaris/Nexenta2.0rc1/snv_104/i86pc/5.8.8/gcc-4.2.3:         0.99_02PRE-r611
VMS/OpenVMS/V7.3-1/alpha/5.8.7/DEC cc 60590001:(5)           FAIL
(XS) only XS works on this platform
(1) Sun C used to compile perl, gcc used to compile Proc::Exists
(2) c/ansi c used to compile perl, gcc used to compile Proc::Exists. 
also, since a gcc is installed that can only emit 64 bit binaries, only
perl64/xs was tested (perl32 passed pureperl tests though)
(3) gcc used to compile perl, icc used to compile Proc::Exists
(4) built&tested by someone else: http://trouchelle.com/ppm/Proc-Exists.ppd
(5) "make" lives in the binary "mmk" on VMS

--- platforms tested via cpants ---
## see: http://www.nntp.perl.org/group/perl.cpan.testers/$test_id
## note: the above platforms/perl combinations are omitted b/c they
## were tested by the author before upload ( except in 0.14, oops ;-) )
platform        | perl versions       | test_id(s)
--- 0.15
freebsd6.1/x86  | 5.6.2,5.10.0        | 1758565,1758342
linux2.6/x86    | 5.6.2,5.10.0,5.11.0 | 1759827,1755611,1767624
netbsd3.1/x86   | 5.6.2,5.8.x,5.10.0  | 1763365,1763372,1763358
darwin-osx/ppc  | 5.6.2,5.8.8,5.10.0  | 1757567,1757571,1757565
solaris9/sparc  | 5.10.0              | 1762196
--- 0.14 (mistaken release, broke 5.5.x/XS)
--- 0.13
freebsd6.1/x86  | 5.10.0,5.6.2,5.5.5  | 1738784,1727352,1727263
freebsd7.0/x86  | 5.10.0,5.11.0       | 1641915,1638524
irix6.5/mips    | 5.8.8               | 1610056
linux2.6/x86    | 5.6.2,5.10.0,5.11.0 | 1736939,1710302,1706516
netbsd2.1/alpha | 5.10.0              | 1610123
netbsd3.1/x86   | 5.6.2,5.8.x,5.10.0  | 1604170,1604221,1604165
netbsd4.0/x86   | 5.10.0              | 1638524
openbsd4.1/x86  | 5.11.0              | 1667882 
darwin-osx/ppc  | 5.6.2,5.8.8,5.10.0  | 1603341,1603349,1603336
solaris9/sparc  | 5.10.0              | 1610143
--- 0.12 (not done)
--- 0.11 (not done)
--- 0.10
cygwin1.5.24          | 5.8.8,  5.10.0, 5.11.0
freebsd6.1/x86        | 5.5.5,  5.6.2,  5.8.8,  5.10.0, 5.11.0
freebsd6.2/amd64      | 5.5.5,  5.6.2,  5.8.8,  5.10.0
freebsd6.2/x86        | 5.8.8,  5.10.0
linux2.6/alpha        | 5.10.0, 5.11.0
linux2.6/x86          | 5.6.2,  5.10.0, 5.11.0
linux2.6/amd64        | 5.10.0, 5.11.0
netbsd2.1.0/alpha     | 5.10.0
netbsd3.1/x86         | 5.6.2,  5.8.8, 5.10.0
netbsd4.0/x86         | 5.10.0
openbsd4.1/x86        | 5.8.8,  5.10.0
openbsd4.2/x86        | 5.8.8
darwin-osx-7.9.0/ppc  | 5.8.1
darwin-osx-8.10.0/ppc | 5.6.2,  5.8.8,  5.10.0, 5.11.0
darwin-osx-8.10.1/x86 | 5.10.0
solaris9/sparc        | 5.8.8,  5.10.0
solaris10/x86         | 5.8.8,  5.10.0
winxp/sp2/strawberry  | 5.10.0

--- untested platforms ---
win:   ia64/amd64 windows, non-NT windows: winME, w98, w95.
other: VMS, macOS<10, BeOS, RISCOS, Netware3, etc.

