Strictly speaking, the BeOS shell environment, bash, provides an excellent system scripting language. O'Reilly even has a book about it. This is the equivalent of Unix shell scripting, though, and not to everyone's taste.
There are implementations, ports, of both perl and python available for the BeOS. Excellent ports, they do not (yet) include support for any BeOS-specific features like file system attributes and queries. Check BeWare to find download links and more information:
Even more sophisticated that these, the BeOS provides a language-independent scripting API, built into the software Kits. This means that all BeOS applications have this support built-in, automatically. Because the BeOS is inherently object-oriented and the messaging scheme in our system is extremely rich, we feel we provide some unique scripting opportunities.
Every application can easily fit into and extend this framework, allowing it to be scripted from any BeOS compatible scripting environment (e.g., a BeOS version of Frontier or perl). Applications can control other applications without being a "scripting environment." Any application can send any other application a scripting-like message.
In the BeOS, script messages are no different from regular messages (like a MOUSE_DOWN being reported by the system). In addition, pure interapplication communication (IAC) will use the same messaging and object model, allowing applications to communicate.