There is a shorter and a longer test suite. And both can run with more or less reporting. After making the newlisp executable do from the main distribution directory: For a short suite and less reporting: make test For a short suite with full reporting: make check For a long suite with less reporting: make testall For a long suite with full reporting: make checkall On a modern machine just do a 'make testall'. I normally do: make clean; make; make testall all in a row separated by semicolons. On Windows, I work in a MSYS Bash shell. When you write a qa-xxx, write your diagnostics, whatever else, to the console. At the end do a: (println ">>>>> SUCCESSFUL") or a: (println ">>>>> PROBLEM ") 'make test' and 'make testall' basically run check and checkall but only report lines with at least 3 angle brackets ">>>". You can run a single qa- file, as an example: ./newlisp qa-specific-tests/qa-net6 Most qa-xxx files are in the qa-specific-tests/ directory, but there are two 'qa-xxxx' files in the main directory: 'qa-dot' and 'qa-comma'. Both do a quick test of all functions in the system. qa-dot does for locales with a decimal "." dot and qa-comma does for locales with a decimal "," comma. I also use qa-dot and qa-comma to check for cell or memory leakage. Comment out the last 'exit' statement in the script and report (sys-info). From the newlisp command line do several (load "qa-dot") to check for cell leakage. After no more than two invocations the cell count should remain constant. Once in a while I use 'valgrind' to check for general memory leaks. For main releases, I also check some files from the example/ directory and run the old modified Debian benchmark suite and applications offered at newlisp.org (the wiki and the ide).