The kind of development you decide to do depends largely on what you need to accomplish and what you are capable of doing, so it's really an individual decision. For example, you may be a C++ programmer who is interested in creating a compiled plug-in for Autodesk Softimage; or you may be a technical director who just needs to automate some repetitive tasks.
Softimage's SDK can accommodate both types of users, since it provides support for both C++ programmers and script authors. The SDK consists of these APIs:
The Scripting Command API—provides access to the same commands that drive the Autodesk Softimage user interface. This is a great API to get started with, since most commands are logged to history, so you can find out how to script in Softimage interactively.
The Softimage Object Model—can be used either with the Active Scripting Engine to create VBScript, JScript, PerlScript and Python scripts or any .NET language, such as C#.
The C++ API—pure C++ development kit available to create compiled library files for plug-in and shader development for Softimage.
For more information on these APIs, see Understanding the Softimage SDK Architecture.
In addition, the dotXSI file format provides a text-based file conversion format which comes with its own API, the Crosswalk SDK. Together, these features allow you to import and export information between Softimage and another 3D animation package or a game engine.