Old School Stylish

From the introduction:

Old School Stylish is a supplement for Old-School Essentials (OSE) that replaces its class system with one that focuses on what your characters do and find in the game world. Instead of picking a class from a list and following its ability progression, your characters will find dusty manuals in time-lost libraries, petition or rescue masters in hopes of learning their secrets, or even invent their own techniques.