Toolset to test scripts before submitting query?

Was trying to find information on setting up multi-step scripts, and came upon the Documentation page; however the docuemntation page states the below for validating script attempts:

"Pagetest has a scripting capability that lets you automate a multi-step test (for example, logging into a site or sending an e-mail message). The scripts are contained in files where a single file constitutes a browser session (the browser will be closed after the script is complete). The files are plain text files and can be edited by any text editor.

You can test a script in the desktop version by selecting “Run Script” from the File menu."

As far as I have been (un)able to find Pagetest is not available / updated any longer, is this a correct finding? If so what scripting tool(s) would be best for validating that a script will work prior to throwing it at