`< /dev/null` is used to instantly send EOF to the program, so that it doesn't wait for input (`/dev/null`, the null device, is a special file that discards all data written to it, but reports that the write operation succeeded, and provides no data to any process that reads from it, yielding EOF immediately). `&` is a special type of command separator used to background the preceding process.
Without knowing the program being called, I do not directly know why it is required to run it in this way.