mstrip is a JavaScript based microstrip analysis/synthesis calculator. It is designed to be easy to use and fairly accurate. The accuracy is generally within a percent or so for the characteristic impedance which greatly exceeds the simplified formulations found in most text books.
https://dmcmahill.github.io/mcalc/
To install this package, simply clone the repo or download a zip and copy all the files in the archive to the installation directory.
To use this pacakge, just point your JavaScript capable web broswer at the file 'index.html'.