air_exec                Path to 'air' executable
chrome_exec             Path to 'Google Chrome' executable
excel_exec              Path to 'Microsoft Execl' executable
exec_available          Check executable availability and version
exec_locate             Find an executable
exec_version            Get executable version
firefox_exec            Path to 'Mozilla Firefox' executable
is_osx                  Test if the system is "macOS"
is_unix                 Test if the system is "unix"
is_windows              Test if the system is "Windows"
libreoffice_exec        Path to 'LibreOffice' executable
node_exec               Path to 'node.js' executable
npm_exec                Path to 'npm' executable
pandoc_exec             Path to 'pandoc' executable
pip_exec                Path to 'pip' executable
powerpoint_exec         Path to 'Microsoft PowerPoint' executable
python_exec             Path to 'python' executable
word_exec               Path to 'Microsoft Word' executable
