PhpSpreadsheet

PhpSpreadsheet is a library written in pure PHP and offers a set of classes that allow you to read and write various spreadsheet file formats such as Excel and LibreOffice Calc.

https://phpspreadsheet.readthedocs.io/

Charts.css

CSS data visualization framework

https://chartscss.org/

4 Useful Web Development Tools That Stay Under The Radar

https://blog.nickbulljs.com/4-useful-web-development-tools-that-stay-under-the-radar

Top 5 Backend Programming Languages

https://medium.com/backenders-club/top-5-backend-programming-languages-4008aa08f376

Centering in CSS

https://web.dev/centering-in-css/