Many numeric libraries do have support for various random generators and could be used to write own monte carlo programs. Some commercial products are available, which often offer the monte carlo methods together with spreadsheets or decision support systems. Cristal Ball from Decisioneering,Inc. If you want to apply monte carlo methods, you do need statistical support functionality to get the input distributions right and to interpret the results. The range of software is broad here.
Some packages have several statistic functions integrated, others rely on external programs.
For completeness i link only to statist , which is small tool for standard statistical tasks. Carlo Sensitivity and Uncertainty Analysis.