The functionality of Olex2 can be extended on two levels: though macros and through python scripts.
There is a simple macro language, where you can group common tasks (and also redefine commands!). The built-in macros will be extended (and replaced!) with those macros you will find in the file you will see when you type
You can also script Olex2 using Python. All functions of Olex2 can be accessed and highly complex functionality can be added.