It's aimed at online programming challenges, homework assignments etc.
- shielding of guest programs from the rest of the operating system: the processes run in a seccomp jail and can only execute a very limited set of system calls (read/write to pre-opened pipes, gettimeofday, exit, etc.)
- memory limit: limit the amount of memory guest processes are able to consume.
- time limits: abort function calls to guest programs after a time limit has elapsed.
- unified interface: all language interpreters are initialized in the same way.
- unified data types: pass strings, integers, floats, nested arrays and booleans back and fro from all guest languages using a common API.
- callback functions: invoke callback functions defined in your application e.g. to query for state, deliver results or write debug output. Function calls are serialized through pre-opened pipes to communicate with the sandbox the guest programs run in.
- multiple simultaneous programs: any number of guests running in a single application.