Best/Worst COTS desktop software APIs

I've had to work with some horrible APIs for proprietary software in my time, and I'm interested in knowing other people's experiences.

I'll start with my worst: Photoshop!

-Terrible documentation

-Multiple conflicting APIs

-Super steep learning curve in some parts

-APIs that never escape beta before deprecation

-Cut-down and locked down environments (JavaScript)

-Impenetrable internal scripting syntax

-Key aspects of the application locked out from scripting

Above is with CS6 - I haven't used CC (customer still on CS6 :| )