“Calculating distance using MySQL” is a very useful blog post for everyone who works with geographical location data and MySQL. It shows a simple example of how to calculate the distance between two coordinates on a sphere (Earth in particular) within the MySQL itself.
I came across the GDPR Expert service via this HackerNews thread. It is a service that helps website owners with the GDPR compliance. Behind the scenes, there is this open source tool, which scans for cookies and provides the details about the vendor and purpose of each identified cookie. The database includes more than 10,000 known cookies.