Redis has introduced a module system that allows developers to write C libraries and add new capabilities and data structures to Redis. This feature is considered one of the most exciting new features in Redis and will significantly shape its dynamics and usage in the future. Modules are basically C shared libraries (.so files) that Redis can load at runtime or on startup, containing command handlers with a specific signature. The API for writing modules is well-documented but extensive; this guide serves as a basic overview of module writing.