Dawn of the Geeks

Yet another DMOZ

Believe it or not DMOZ can run very efficiently even on an old 700Mhz system. The trick is encoding the directory name as an MD5 and storing all the contents for that directory in a serialized array. When you visit the site it just sets the dir to all lower case, MD5’s it and pulls the row from the database. As an added trick the first 2 characters of the MD5 define which table to look in.

The data is deserialized into an associative array and rendered. Simple, fast.