Suggest the name of software tools mostly used by Web Hosting companies

I should make video tutorials on which software tools to help web hosting companies enrich the Knowledgebase/Support of their website. I have made video tutorials on cPanel, SolusVM, Outlook 2019. Please suggest name of other software whose video tutorial a hosting company must have.

WHMCS is a popular web hosting software that can simplify and automate daily tasks and operations relating to your web hosting business. It can integrate with all the leading control panels and service providers like Cpanel, Plesk, etc.

Thanks for your suggestion Jesica!