yonkeltron@Akiba:~$ jruby1.0 -h
Usage: jruby [switches] [--] [rubyfile.rb] [arguments]
    -e 'command'    one line of script. Several -e's allowed. Omit [programfile]
    -b              benchmark mode, times the script execution
    -Jjava option   pass an option on to the JVM (e.g. -J-Xmx512m)
    -Idirectory     specify $LOAD_PATH directory (may be used more than once)
    --              optional -- before rubyfile.rb for compatibility with ruby
    -d              set debugging flags (set $DEBUG to true)
    -v              print version number, then turn on verbose mode
    -O              run with ObjectSpace disabled (improves performance)
    -S cmd          run the specified command in JRuby's bin dir
    -C              pre-compile scripts before running (EXPERIMENTAL)
    -y              read a YARV-compiled Ruby script and run that (EXPERIMENTAL)
    -Y              compile a Ruby script into YARV bytecodes and run this (EXPERIMENTAL)
    --command word  Execute ruby-related shell command (i.e., irb, gem)