I made an interpreter to test programs written in this little rpn language.

source: http://www.msu.edu/~shawjef3/lrpn.ml
windows binary: http://www.msu.edu/~shawjef3/lrpn.exe

Usage:
lrpn program stackval1 stackval2 ... stackvaln

For example, add 1 to each member of a 2-member stack.

lrpn 1+s1+s 5 6

yields:

6 7

Sometimes you will need to quote your program. For instance, "~1&" won't work on windows due to the shell thinking you are sending it commands. However quoting fixes that.

lrpn "~1&" 1

yelds 0, telling you that 1 is an odd number.